I'm getting checksum failed with SP 0.43.00 and radioactive 0.43.00-RA2 with a fresh extract.
I tested both of the archives and they aren't corrupted. I'm running it on Linux Mint if that matters.
Double checked on this end and the checksum reads as okay on a fresh install. The problem won't be in the base game, as Radioactive does not check those files (it would take far too long for something that's just supposed to be a sanity check).
I do not have the means to test on Linux. Perhaps the checksum library works differently there (although the checksum works okay on Mac, so...). The fact that you got a checksum message at all suggests the mod is at least partially installed correctly. You could give it a try and see if its working.
If you want to check if the checksums are indeed different on your computer, you could type
call WriteMD5(True) into the console to generate a new file for your machine (
game/radioactive/RaMD5.json) and then compare it to the original in the archive.
(This is getting into Dev territory here, so don't do this readers unless you already have some idea of what I'm talking about.)