Publishing Errors

Ok, this happened often in RW 5 and now it’s happening all the time in RW6!

When I make an update to the site that might include some stacks and i go to publish it (although it previews perfectly) many times it will publish bizarrly with errors. I would make some adjustments and try to publish again and I get

Exception while exporting site

Error: Could not copy /var/folders/fp/9wj8f7l916x6855cphbttry40000gn/T/com.realmacsoftware.rapidweaver6/stacks-18AAAE58-2DDA-4FF1-9C98-8B48E82B06B8-nfuVRN/stacks-image-C2086AC.jpg to /var/folders/fp/9wj8f7l916x6855cphbttry40000gn/T/com.realmacsoftware.rapidweaver6/RapidWeaver/59061/document-106102876252672/RWPublishing/files/stacks-image-C2086AC.jpg.

Then i have to close off my site. shut down RW and restart it and then i can publish again but only once! It will work and if i try again i get the same message!!!

Has anyone had this problem?