@ DanelSonic123: Unfortunately this is a common problem. Of course there is no virus infection in the dedicated server. I assume it's detected as virus because it uses UDP sockets for network communication, writes files (logs) etc. These are suspicious things because malware would contain similar operations.

@ medeiros: You can edit the config file in sys/controls.cfg manually if nothing else helps (stop the game first). Weird issue though

Regarding the key issues: I know that SQ did some adjustments especially for the console key. Maybe he has an idea why there are problems or how to solve it. Might also be related to medeiros key assignment problem somehow.

First, you login via Steam.
If you change your Steam nickname then try to open CS2D again, it will be failed to login.

@ medeiros: Maybe it's due to the custom Steam skin? (Mine looks fine, as seen here) As for unlocking achievements, it just takes time to register, that's all.

$ sudo apt install libgtk2.0-0:i386 libidn11:i386 libglu1-mesa:i386 libpangox-1.0-0:i386 libpangoxft-1.0-0:i386

Reading package lists... Done
Building dependency tree
Reading state information... Done
libglu1-mesa:i386 is already the newest version (9.0.0-2.1).
libpangox-1.0-0:i386 is already the newest version (0.0.2-5).
libpangoxft-1.0-0:i386 is already the newest version (1.38.1-1).
libgtk2.0-0:i386 is already the newest version (2.24.30-1ubuntu1.16.04.2).
libidn11:i386 is already the newest version (1.32-3ubuntu1.2).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded

Regarding the key issues: I know that SQ did some adjustments especially for the console key. Maybe he has an idea why there are problems or how to solve it. Might also be related to medeiros key assignment problem somehow.