Serious error occurred with my Cloud

Hello,
Recently I experienced some problems with my Cloud. This error is the most recent one and I don’t have any solution for it. I don’t know if a problem with my PC or the Cloud is. Please help with this error. Can you recommend me some different Clouds that will work without any problem?
Thank you!

Error
We’re sorry, but a serious error occurred. Please don’t close the Cloud Flow Designer window. Contact salesforce.com Customer Support as soon as possible. OK
