File size cannot be retrieved. File might be too large…

If BackWPup displays the message

File size of “%s” cannot be retrieved. File might be too large and will not be added to queue.

then the backup folder contains a file that is too large for backing up.

Note: This error message points toward your server running with 32 bit PHP. Please upgrade PHP to the 64 bit version if possible. Contact your hosting provider for assistance. An upgrade to 64 bit should take care of the above problem.

With 32 bit PHP, files larger than 200 MB can cause a backup failure every time. Your other option – if you can’t upgrade to 64 bit PHP – is to either delete the file if it is no longer needed or to simply exclude it from the backup.

Refer to this document for instructions on how to exclude files and directories: How to exclude files and directories