When did Blender's API change from version 2.42 to the most current API?

I’ve read a few posts where users can’t load older python scripts in thte latest releases due to changes in the API. How are older scripts getting ported? Is the process difficult, or just a matter of changing or adding a few lines of python code? I’ve been using Blender on and off for years now and still don’t understand it all that well. I’ve modified a few text based scripts for another modeling software called, Anim8or 097 preview with the help of another A8 user and the process is very similar to python scripting language only using a scripting language loosely based around C and C++ refered to as ASL. I have a few questions that perhaps some could clarify for me. Does Blender support a script checking routine/utility? Anim8or, supports one that when run will flag any obvious errors it locates and display the output in a seperate pop up window. Does Blender use something similar that I can use to test my scripts? If so how do Blender users access this function? Thanks, Leroy.

How are older scripts getting ported?

Official scripts were ported by the dev team. Most others by the original author if they were still active Blender users when the API was updated. So quite a few are not ported and may never be ported. Some have been re-designed and improved.

Is the process difficult?

In most cases this task lies beyond the reach of a casual user. So yes.

Does Blender support a script checking routine/utility?

Yes, if your script fails to run, open up or switch over to the console and you will see the python error. On Windows this console is hidden by default so you must launch Blender with the ‘-con’ command flag to make the console appear on launch. On OSX you have to open the system console and launch Blender from there. I think Linux is the same as OSX.

I see and thank you for the -con tip. I’d really love to learn how to port older scripts to run on the lastest version fo Blender, so if you come across any new posts about the issue please post a link to the source. Thanks, Leroy.