controls created on the thread cannot be parented to a control on a different thread

Suddenly a message of lost connection appeared while I was working on my project online. It told me I lost my connection and that I have the option to work offline or to close without saving. I decided to work offline to try to save my work, but even if I waited a lot the message stayed there without letting me work on my project. After some time I decided to press "close without saving and the popup disappeared. Nevertheless bizagi was blocked and no way to start working again. At that point I restarted my pc and force the bizagi closing. When I opened it again, the project was offline and no way to go back online. When I try to go online it gives my the error "controls created on the thread cannot be parented to a control on a different thread". How can I solve?