Hello.
Incremental file verification didn't success, so you can either run a surebackup job to make sure the backup is recoverable or not or just run an active full to avoid the file corruption in later increments of the chain.
You can also contact technical support team to review the log.
Thanks.
There is no point in running SureBackup job against a corrupted/unreadable backup, as the result is obvious
Best is to have our support perform log review to find the real cause and make sure this does not happen again.