Normally, all REXX programs written in Classic REXX should run under Object REXX without any changes. But there are some minor changes and bugs in Object REXX that might lead to an error in your Classic REXX programs.
The first thing you should do, if you're got an error in a Classic REXX program running under Object REXX, is:
Look in the Object REXX online documentation; especially read the section Migration (the good old RTFM)!
If you do not not find anything related to the error there, you can take a look at the following sections with differences between Classic REXX and Object-Oriented REXX!
Please use only this order for checking for problems, because I'm not going to repeat the facts already mentioned in the Object REXX online documentation.
OK, now that it's hopefully clear what information you can find in this section, let's begin.