GZip gives error: java.util.zip.ZipException: invalid block type

Debug may take little wrong process for troubleshooting and it might create impact with existing traffic if device is in production, Correct me if i am wrong.

Personally I would recommend you use existing iApp feature in F5. Below link may help to generate UCS...

https://devcentral.f5.com/codeshare/f5-iapp-automated-backup-1114