Sync to disk fails after upgrade to Seafile server 6.2.5

After updating from 5.0.3 (OK, that was quite old) to 6.2.5 I can not sync some libraries with Seafile Client 6.1.4 to my laptop any more. Under the library the client is mentioning “connect to server” all the time and when I open the library with the web client I can see on every file “fetch failed”. I found out that this is only happen if the library was created in the very beginning with Seafile server 2.x where the creation date (it always displays 1970) is not there any more due to the change of library format at that time.

Is there any way to fix that?

If not, how can I find out which libraries of which users have these “1970”-Problem? Is there any way to get a list of the creation date of libraries?

Many thanks in advance.

Did you already try to remove the cache directory of Seahub via rm -rf /tmp/seahub_cache ?