1) Don't have the 'return bug' in it.
What is the return bug? Tried searching, probably out there somewhere but dont see the need to read up pages of stuff for a one liner answer.
2) Upgraded to the latest versions of tools like newgen (if you use it).
Where can I download this? Heard theres new tools avaliable but looked everywhere, some good links to mapping tools and all that can help make my map will be good. We here at DaL project are fans of DaL, not warcraft. So my noobiness is no surprise.
3) Haven't used any editors like WEU that may cause corruption.
What that?
Just update WC3 and edit your map.
If you used JASS, then make sure the return bug was not used.
If the return bug was used, consider using hashtables and the new natives.
Some GUI actions will error, if that is the case then you will have to remake all the triggers for the map.