Xpra: Ticket #2030: xpra "Error: unknown modifier 'mod3'" @shadow

Windows 10 (17362.320) client to Ubuntu 16.04.5 LTS server

During an otherwise-normal working xpra shadow session, I get:

2018-11-05 21:15:05,781 client @26.140 server is OK again
2018-11-05 21:26:42,569 Warning: failed to add the following modifiers:
2018-11-05 21:26:42,569  mod1
2018-11-05 21:26:42,569  keys still pressed={64: 'Alt_L'}
2018-11-05 21:26:42,569  doing a full keyboard reset, keys now pressed={64: 'Alt_L'}
2018-11-05 21:26:53,352 Warning: failed to add the following modifiers:
2018-11-05 21:26:53,353  mod1
2018-11-05 21:26:53,353  keys still pressed={64: 'Alt_L'}
2018-11-05 21:26:53,354  doing a full keyboard reset, keys now pressed={64: 'Alt_L'}
2018-11-05 21:26:57,390 Warning: failed to add the following modifiers:
2018-11-05 21:26:57,390  mod1
2018-11-05 21:26:57,391  keys still pressed={64: 'Alt_L'}
2018-11-05 21:26:57,391  doing a full keyboard reset, keys now pressed={64: 'Alt_L'}
2018-11-05 21:27:35,779 Error: unknown modifier 'mod3'
2018-11-05 21:27:35,805 Error: unknown modifier 'mod3'
2018-11-05 21:27:35,855 Error: unknown modifier 'mod3'
2018-11-05 21:27:35,916 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,011 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,039 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,103 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,119 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,203 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,231 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,303 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,389 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,389 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,427 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,471 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,520 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,536 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,569 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,589 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,630 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,703 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,704 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,719 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,780 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,834 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,860 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,903 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,966 Error: unknown modifier 'mod3'
2018-11-05 21:27:36,967 Error: unknown modifier 'mod3'
2018-11-05 21:27:37,058 Error: unknown modifier 'mod3'
2018-11-05 21:27:37,114 Error: unknown modifier 'mod3'
2018-11-05 21:27:37,238 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,063 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,093 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,165 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,189 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,219 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,284 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,297 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,320 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,343 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,383 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,419 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,443 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,496 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,590 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,614 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,714 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,755 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,760 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,806 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,813 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,836 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,881 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,947 Error: unknown modifier 'mod3'
2018-11-05 21:27:51,950 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,044 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,094 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,098 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,158 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,222 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,247 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,292 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,345 Error: unknown modifier 'mod3'
2018-11-05 21:27:52,492 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,316 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,327 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,390 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,438 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,629 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,701 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,725 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,828 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,857 Error: unknown modifier 'mod3'
2018-11-05 21:28:31,857 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,056 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,103 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,230 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,276 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,277 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,318 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,354 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,355 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,413 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,477 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,501 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,551 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,593 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,594 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,646 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,684 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,741 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,760 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,838 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,883 Error: unknown modifier 'mod3'
2018-11-05 21:28:32,975 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,168 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,236 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,238 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,339 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,362 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,512 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,530 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,563 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,664 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,664 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,664 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,711 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,761 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,761 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,772 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,869 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,869 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,871 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,944 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,984 Error: unknown modifier 'mod3'
2018-11-05 21:28:33,985 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,003 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,063 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,099 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,123 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,165 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,199 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,323 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,364 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,365 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,370 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,370 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,402 Error: unknown modifier 'mod3'
2018-11-05 21:28:34,435 Error: unknown modifier 'mod3'
2018-11-05 21:28:35,902 Error: unknown modifier 'mod3'
2018-11-05 21:28:35,980 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,230 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,302 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,426 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,467 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,513 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,531 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,563 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,601 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,703 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,733 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,878 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,932 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,985 Error: unknown modifier 'mod3'
2018-11-05 21:28:36,985 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,182 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,230 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,253 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,315 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,356 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,439 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,441 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,464 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,498 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,668 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,734 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,798 Error: unknown modifier 'mod3'
2018-11-05 21:28:37,895 Error: unknown modifier 'mod3'
2018-11-05 21:28:53,603 Error: unknown modifier 'mod3'
2018-11-05 21:28:53,629 Error: unknown modifier 'mod3'
2018-11-05 21:28:53,679 Error: unknown modifier 'mod3'
2018-11-05 21:28:53,794 Error: unknown modifier 'mod3'
2018-11-05 21:28:53,869 Error: unknown modifier 'mod3'
2018-11-05 21:28:53,989 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,041 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,169 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,178 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,203 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,231 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,256 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,262 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,303 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,359 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,393 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,443 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,467 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,579 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,586 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,613 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,653 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,730 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,732 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,738 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,761 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,805 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,848 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,928 Error: unknown modifier 'mod3'
2018-11-05 21:28:54,929 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,019 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,054 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,078 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,120 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,166 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,220 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,258 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,327 Error: unknown modifier 'mod3'
2018-11-05 21:28:55,456 Error: unknown modifier 'mod3'
2018-11-05 21:34:21,066 client @41.420 window-close event on desktop or shadow window, disconnecting

The only thing I remember not working, is that after some time, I couldn't change the language. Layouts are (en-us, el-gr), and I remember en-us --> el-gr transition working (on both computers), and then failing to do so on the shadowed server (client host switched normally)

The "special" keystrokes that I might have used (non-inclusive) are:



Tue, 06 Nov 2018 13:50:03 GMT - Antoine Martin: owner, description changed

The handling of modifier keys for shadow sessions probably needs more work.

The only thing I remember not working, is that after some time, I couldn't change the language.

What do you mean by "change the language"?

Layouts are (en-us, el-gr), and I remember en-us --> el-gr transition working (on both computers), and then failing to do so on the shadowed server (client host switched normally)

How do you "transition"? For more keyboard debug guidelines, see wiki/Keyboard

Please provide specific steps and / or the server -d keyboard debug log for specific problematic keys.


Fri, 16 Nov 2018 00:02:34 GMT - stdedos:

I hope there was something of those mod3 messages.

I did it in 2 rounds: First I tried to play with the language-change shortcuts, then I did the Ctrl+Alt(+Shift)+Arrows.


Fri, 16 Nov 2018 00:02:51 GMT - stdedos: attachment set


Mon, 19 Nov 2018 06:10:22 GMT - Antoine Martin: owner, status, component changed

Looks like many key translations aren't working for modifiers:

change_mask(add) ('shift',) modifier 'shift' using keycode 50, success: False
change_mask(add) ('mod1', 'shift') modifier 'mod1' using keycode 108, success: False

Found a minor bug: r21029.

I think we need a translation map for modifiers when connecting to shadow servers.


Thu, 29 Nov 2018 08:01:36 GMT - Antoine Martin:

Could be solved by #1716.


Fri, 30 Nov 2018 18:11:24 GMT - Antoine Martin: owner, status changed

The mod3 issue, aka keynames_for_mod not assigned yet should be fixed in r21174. (more details in ticket:1716#comment:4)

Those log files you attached are way too big and include all debugging rather than just -d keyboard I asked for, so I can't use them. Please also answer the rest from comment:1, in particular how you "transition".

First I tried to play with the language-change shortcuts, then I did the Ctrl+Alt(+Shift)+Arrows.

What are the language change shortcuts? Why the arrows?

Note: if your shadow server is not configured with the languages that your client needs, then things will not work: we don't change the server keymap configuration in shadow mode, we just try to adapt to it.


Sat, 01 Dec 2018 09:06:07 GMT - stdedos:

Replying to Antoine Martin:

Please also answer the rest from comment:1, in particular how you "transition".

From language to language?? By LAlt+LShift/LWinKey+Space shortcut (both server and client know this shortcut) "Change the language", "transition (from language to language)": Press the shortcut, so that keyboard layout changes between en-us and el-gr.

First I tried to play with the language-change shortcuts, then I did the Ctrl+Alt(+Shift)+Arrows.

What are the language change shortcuts? Why the arrows?

In Ubuntu, you can change workspace with Ctrl+Alt+Arrows. Workspaces can be in any 2D layout (mine are setup as 3x3). You can drag a window with you to a layout by also pressing Shift (i.e. Ctrl+Alt+Shift+Arrows)

Note: if your shadow server is not configured with the languages that your client needs, then things will not work: we don't change the server keymap configuration in shadow mode, we just try to adapt to it.

This sounds to me as related to #2047. However, I don't understand this comment. Both being my computers, both have en-us, el-gr layout (that I can change with LAlt+LShift or LWinKey+Space shortcut).


Sat, 01 Dec 2018 09:25:03 GMT - Antoine Martin:

... Press the shortcut, so that keyboard layout changes between en-us and el-gr.

The exact configuration for this X11 feature would be in the keyboard debug information requested in comment:1. (see wiki/Keyboard)

In Ubuntu, you can change workspace with Ctrl+Alt+Arrows. Workspaces can be in any 2D layout (mine are setup as 3x3).

Does this have anything to do with this keyboard mapping issue?

Both being my computers, both have en-us, el-gr layout

Then things should work. Again, without the debug information requested, we don't know for sure.

If the configuration is identical, you may want to try the --keyboard-raw=yes feature.


Sat, 01 Dec 2018 09:33:03 GMT - stdedos:

Replying to Antoine Martin:

... Press the shortcut, so that keyboard layout changes between en-us and el-gr.

The exact configuration for this X11 feature would be in the keyboard debug information requested in comment:1. (see wiki/Keyboard)

I will try to get them as soon as possible. However, I don't have constant access to the laptop client and the shadow server (e.g. not this weekend). It is also complicated since, I need to also unlock the shadow server's lockscreen and then enable the keyboard diagnostics.

In Ubuntu, you can change workspace with Ctrl+Alt+Arrows. Workspaces can be in any 2D layout (mine are setup as 3x3).

Does this have anything to do with this keyboard mapping issue?

It is one of the "weird" keyboard shortcuts, that might have been the offending one. Trying it after "this situation" has triggered, it did produce extra lines of the 2018-11-05 21:28:33,664 Error: unknown modifier 'mod3' message However, as I haven't noticed the repeating message from the beginning, I don't remember how this situation was triggered.

Both being my computers, both have en-us, el-gr layout

Then things should work. Again, without the debug information requested, we don't know for sure.

If the configuration is identical, you may want to try the --keyboard-raw=yes feature.

I'll try it after I generate some diagnostics for this issue


Thu, 31 Jan 2019 13:20:05 GMT - Antoine Martin:

Can I close this?


Thu, 31 Jan 2019 14:48:31 GMT - stdedos:

Replying to Antoine Martin:

Can I close this?

If you feel like it, I guess. However, with the antivirus issue, and now the py2-server_py3-client issue (I am having heavy connection interrupts with cause unknown) haven't allowed me to actually do anything for this ticket.


Thu, 31 Jan 2019 14:51:51 GMT - Antoine Martin:

However, with the antivirus issue

You mean #2088. I have received an email saying that the issue was fixed in their latest database update.

and now the py2-server_py3-client issue

No idea what this one is. Did you create a ticket?


Fri, 01 Feb 2019 13:05:59 GMT - stdedos:

Replying to Antoine Martin:

However, with the antivirus issue

You mean #2088. I have received an email saying that the issue was fixed in their latest database update.

It came a bit later for me (I commented on the original ticket). I have it now fixed

and now the py2-server_py3-client issue

No idea what this one is. Did you create a ticket?

Not yet, because I am not sure what to report. Except "OMG WTF client unresponsive 5/5"

I am not sure what information to collect either, so I was trying to get some understanding of it. I also wanted to verify that it was not due to bandwidth issues.

One of the tickets is #2131, and I think I would need to create more, if I was "forced" into Py3 xpra.


Thu, 14 Mar 2019 12:58:24 GMT - Antoine Martin: status changed; resolution set


Sat, 23 Jan 2021 05:40:17 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/2030