Exception in CellProfiler core processing

I am getting this (in the title) error message in CP 2.1.0 EVERY TIME I try to load a project that I have previously created and used (several times…)
When I try to load my images first and then open the project my pipeline is empty…
This had occurred quite a few times since I upgraded and I had to rebuild my pipeline from the scratch every time…

Any idea?
I’m on a Mac Pro 2X3.06 Ghz 6-core Intel Xeon; 48 GB RAM


Hi Matteo,
By any chance, had you been using one of our beta releases prior to the 2.1 formal release?