Project saved with ML is hanging v2.1.5 when loading it.

[micheus]

No body else has complained of something like this happen - I also use to reopen my old projects in all newest versions and couldn't notice that too.

It's hard to investigate a issue like that without the file, so I would ask you to do any test that could help us to try help you.
ML stays on 2.0.1. So, maybe you would check if it can be load by the v2.0.2 that contains some fixes.

I also would suggest you make a backup of your project and - by loading it at ML - select all objects and in Body selection mode [B] use the CleanUp option; Save it and try to load in Wings3D v2.1.5 again.