Hiya
Oh dear, those messages are not a fun way to start, sorry.
Would you be able to send a screenshot of the error message?
Would you have any more details about the design?
Was a new one you created, or one saved in Fusion Desktop?
Was it simple or very complex, IE 1000s of instances?
We do not currently support direct modeling designs, was it that by any chance?
Let me know and I am sure we can get to the bottom of this.
Jason
Starting Fusion in a browser is working today. I also had problems with viewing one 2D AutoCAD file that was linked into a Fusion file. That issue seems to have resolved itself also, therefore I suspect the issue was on the Fusion servers.