Today I experienced getting error notices when doing Boolean operations on complex geometry. Two or three times, the errors were so numerous that I wanted to kill the operation. However, I couldn't as the only button on the error window would dismiss the message only to error again. There is no way to abort the whole operation. I had to get out Task Manager and kill Modeler. It would be nice if there was a Cancel Button as well as an Okay button. On one operation (I think it was a Union) I hit okay about a thousand times hoping I would come to the end of the errors. But it was getting rediculous so I just killed the program.