As mentioned, the error happens when something goes wrong during the actual compression procedure of the mentioned file to the mentioned archive.
It does not depend on any datfile/collection and since you're using 7z (external packer), running that external tool returns an error on that specific file.
Finding the actual reason..hmm...can be difficult without having the files, so let's check the standard things:
- you've put the path of the 7z.exe to your system's environment %PATH% variable? If not, ensure you've listed the full path to the exe in compressor/settings->7z
- you're using a current version of 7z? 19.00 should be also fine (20x is still alpha)
- for temporary file decompression/compression, cmpro's temp folder is used, so the place where cmpro is installed should have enough free space and cmpro shouldn't be installed in an UAC controlled folder
- you're trying to rebuild to an empty destination (i.e. the file does not exist there already)
- Testint the actual 7z file (source or destination). Did you try tro test it with 7z if it's not corrupt?
- if you do a rebuild from a to b, ensure that the file does not exist in b. Maybe cmpro tries to replace the file in there and something fails during deletion.
- did you try to do the compression manually? So run your commandline statements on the files and check if maybe 7z fails with something
- if you can repeat the scenario, you should send me the files in question (used datfile, the 7z source, the 7z destination if existing)
Typical problems with 7z are solid archives. Like you want to add something to a solid archive while not using solid mode commandline parameters.