Client stops connecting and web does not show libraries


After two years working (Windows seafile server version 6.0.4), now client is not able to connect (it connects to other servers).
The web server still connects, but, it takes a lot of time, and at the end does not show libraries, only menus.

I suspect some database corruption, but not sure. Also, it seems a lot of tcp/ip connections.

What test I could do?
Is there any script to repair database structure.

Are there any errors in the logs?