Failed: error - index error

Client - 2.4.10 -urbackup - ubuntu 18.04

Removed client from the web and did new install on client,added in client on web

Info 03/04/20 16:24 Starting scheduled incremental file backup…
Info 03/04/20 16:24 Backing up “folder1” without snapshot.
Errors 03/04/20 16:24 Error while listing files in folder “folder2”. User may not have permissions to access this folder. Errno is 0
Errors 03/04/20 16:24 Indexing files failed, because of error
Errors 03/04/20 16:24 Constructing of filelist of “servername” failed: error - index error
Errors 03/04/20 16:24 Backup had an early error. Deleting partial backup.