This version sounds very old. The client may have already drop support of such old server version.
Does it run normally before? Why don’t try upgrading the server?
Thanks for your responce, i will try to upgrade the server is there any documentation for upgrading server and we also have around 250 GB data in seafile-server
From a security point of view one should update the server to the latest stable version once its available for several weeks/month.
Running such old software can be a security risk.
Ubuntu 14 is also out of support for quiet a long time now.
Using a local reverse proxy does also make a lot sense, even when on LAN only.
Encrypted communication within LAN is also a best practice one should consider.