Floppies with valid CRC means good data?

[Elektraglide]

I have a set of floppies I recovered a while back (containing Prolog!). All the CRCs show good in the track viewer, but the programs crash when run. I am pretty certain the programs did run back in the day - it cost $3000 back in the day!

Do good CRC indicate good data? Or is it simply the CRC that is generated is from whatever data is on the disks?

[qbarnes]

Each sector has two CRCs, one for its ID and its Data. If both are good, in all likelihood, that's a good sector read. (Multi-bit errors could in theory produce a valid CRC. Very rare, but possible.) However, you also must read all the sectors of all the tracks, and both sides if the media was written double-sided. Sometimes you can completely drop (miss) a sector during a read.

If the floppy is copy-protected, that throws in a whole, new wrinkle into ensuring to get a full and good read.

What OS was the floppies written for and what command did you run to read them?