"NEVER save any file in a compressed format. One place I worked did that with all of their files, only to find out, to late, that the latest uncompress program wouldn't handle the older format."

Some years ago in the age of small HDs, there were clever things that compressed drives to allow more storage. If anything broke, you could not read the disk if you lost certain parts of the drive - it was all encoded. Clever geeks said "Well sod that for a pair of pyjamas" and went 'commando'.... :-)