i think that it is a bug of the new version, i've the same problem and my friends has it too!

I was using cubik when it suddenly closed, I tried to reopen it but it did not work anymore 'giving me this error

https://imgur.com/L6MwCna






https://imgur.com/L6MwCna

so I went to the log folder and this is what was written:

Unity Player [version: Unity 5.5.3f1_4d2f809fd6f3]

CubikStudio ...