Here's the recovered project
.capx files are really just .zip files with a different name, containing a folder project. So you can rename it to .zip, extract all the files, and locate line 941 in Teste.caproj. There you can see the object "espinhosqsaem" has only two collision polygon points (there must be at least 3 to make a triangle), so I added another one at (0, 0) to fix the project, then saved as .capx again and it works.
Can you remember if you were doing something with the collision polygon of the object "espinhosqsaem" just before this happened? We'd like to fix this to prevent it ever happening again. SamCartagenaPR, please also report any similar issues you find as bugs, we really want to fix these issues rather than having to resort to editing project files like this!