Error syncing: "file size 0"

Hi friends,
I've found some problems around the complete file sync on owncloud for Linux (Ubuntu) version owncloud-client_2.3.2-1.1_amd64,,
infact on the owncloud client Activity -> Not Synced, I can see 834 files not synced for this kind of error: "file size 0 byte, aspect size 1345kb".

(I think that the old hosting service has stopped some services, and this could be generate some trouble, now all is on my own Linux VPS)

If I login to the owncloud web interface none of those files are present on its directory.
If I look into the local directory the files are stored correctly and all seem fine.

What I should do for to solve this situation?
Should I copy manually into the ownclowd data folder the missing files?
Or should I delete the local .owncloud config folder for re initialize the sync process?
Or other?

many many thanks!


..I came out of owncloud client, renamed the folder ".local/share/data/ownCloud" and then re-run owncloud client, and set the parameters again.

Not even this is giving results, the second computer does not seem to be able to synchronize.

Can anyone among you give me an indication on how to debug the problem (client or server side)?

many thanks