You've got a Compact Flash (CF) hard drive enabled Amiga, and you've installed a game that is probably "heavy" in graphics and sound (e.g. Syndicate, or Heimdall 2). You can install the game with no problems off of original floppies. But at some point when you launch the game or start to play, the game can't load file data. Or worse, the game crashes and you get a screen with something like, "bad loadfile hunk".
But if you try to play the games off floppies, everything seems to be OK.
That odd message about a bad loadfile hunk means you have damaged, corrupted files. What's going on?
When you installed your CF HDD, the max-transfer rate was set at a rate some games can't use. This is easy to fix.
Grab your Install 3.1 disk. Open up HDToolBox, check the Advanced box then 'Change' to get to the settings. Your max-transfer rate is probably set to something like 0xfe0000. You need to change that to 0x1fe00. Be sure to press "Enter" before you press "OK" or your changes won't actually hold.
Next, delete your previous game installation and re-install the game with the new max-transfer settings in place.