The dots in the compiler window mean two things: At first your script gets compiled and "checked" for syntax errors which probably everyone is aware of. Then however without notice at some point the "..." dots have another meaning, that is the engine is loading and creating engine objects such as SOUND files or apparently view entities.

I don't know but could it be that some other previous file is damaged which then leads to loading errors on subsequent files?

I once had a really weird acknex crash (I think it was of the "acknex.exe has stopped working" type) where indeed the reason was a faulty texture/ bitmap, it's not that uncommon (especially when you consider that MED literally destroys some files on saving if you don't treat it with care - for example on some "unsupported" undo operations the model gets messed up and when you then save it, all hope is lost).