Am 27.03.2017 um 08:25 schrieb Ralf Habacker:
[...] 
With the mentioned patch applied to a local wine build (or with a
renamed wineserver) the site now runs about two weeks and one noticable
change is that the initial
mentioned communication issue did not happens. This let me think that
there may be a long time running issue with wineserver, which affects
the dde interface.

It is nice that you have found a workaround, however we would also like
to fix such issues of course. If you find any way to trigger this issue,
please file a bug report.

I will do but unfortunally I'm not at this point yet. Observations from
the last weeks shows that the error happened two times:

1. wineserver is running 12 days and not restarted because one
application showed a message box, therefore did not quit and blocked
wineserver restart, which let other wine applications dde communication fail
3. Yesterday we had a similar issue: dde communication of newly started applications fails after wineserver was running about 9 days because wineserver restart has been blocked by a still running application.

Currently it is not possible to say what happens in that incubation period and why it does affect dde comunication. We can only say that the main windows application (the engine which generates the graphics print out) has been started about 5000 times in the last ten days and the windows remote control application which uses dde to communicate with the main application runs between 10 and 356 times for each print out.

This indicates that any long time usage of a wine application for example as server backend using dde may have similar issues.  Would it be possible to restart wineserver although applications are still running ? 
2. wineserver is running 3 days and applications dde communications
fails because wineserver has been restarted immediatly
...
applications dde communication fails and wine reports
wine: chdir to /tmp/.wine-37002/server-fd0a-9602c failed: no such file or directory
The related part is located in server_connect() (see https://source.winehq.org/git/wine.git/blob/HEAD:/dlls/ntdll/server.c#l1210)

1210     setup_config_dir();
1211     serverdir = wine_get_server_dir();
1212
1213     /* chdir to the server directory */
1214     if (chdir( serverdir ) == -1)
1215     {
1216         if (errno != ENOENT) fatal_perror( "chdir to %s", serverdir );
1217         start_server();
1218         if (chdir( serverdir ) == -1) fatal_perror( "chdir to %s", serverdir );
1219     }

Guessing from the error message "no such file or directory"  I would say that the error happens in line 1218, which indicates that the server could not be started

Any ideas what could happen here ?

Ralf