Error when accessing the root file

Dear @azinbeigi ,

There are a couple of already answered posts on the forum that might be relevant for your problem (for example here and here).

The error you report in general can mean that either the file was not properly written to disk or if you are reading it from a remote storage facility that something went wrong in the remote read.

Maybe @pcanal has more insights, but I encourage you to take a look at the posts mentioned above and search for similar ones here on the forum.
Cheers,
Vincenzo