Go to Applications/Utilities/Disk Utility, choose your HD and run Repair Permissions on it.
Then try Classic again.
What do you run that requires Classic?
After upgrading to Tiger 10.4.4 (iMac G4) and attempting to start Classic the following message occurs: There is a problem updating the classic specific files. Classic unable to update its files in "System Folder" on in MAC HD". I haven't been able to find a word combination in search mode that addresses this problem. Thank you.