Lost a whole library? "Can't find seaf dir for /".

[Dmitry Sinyukov]

I am using a relatively old version of seafile server (3.0.3) on Ubuntu Server 12.04.

I had a relatively large (~20GB) library which I haven't accessed for a while, but now when I access it even through the web, the browser shows "Sorry, but the requested page could not be found." 

In seafile.log I see the following messages (they appear every time I try to access the library):

[11/15/15 20:48:07] Data does not contain a directory.

[11/15/15 20:48:07] ../common/rpc-service.c(1350): Can't find seaf dir for /

Other libraries seem to work fine.

It seems like here https://groups.google.com/forum/#!topic/seafile/zavGQhuGTAY

they had a similar problem, and upgrading the server fixed their problem, however in their case it was just a sub directory which was not displayed. For me, it's a whole library.

I may try upgrading the server, but I am somewhat concerned about losing the data. Could you please help me to solve the problem. I still hope the data are not lost, because they were somewhat important.