Forum_Admin Hi Pavel, it is really strange...Tried to reproduce on MAMP Pro....
1. Disabled all plugins but problem still exists.
2.Reloaded an older snapshot-->no problem. Update ATUM (leaving the old other plugins as is) and it runs after update in the Error 500: "Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, you@example.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log."
3. Rolling back the ATUM plugin: error remains.
4. The php log does not show any error (except Curl Error : Could not resolve host: www.googleapis.com)
5. On the production server the dashboard loads but now widgets are shown, clicking on add more widgets nothing happens...
Additional Info: rollback to 1.5.5.1 succeeded...there everything is normal.