Click on the sign and see what the error is.
Check that the encoder has been updated to 4.01.
Mine wouldn’t update until I reinstalled AME.
Check 3rd Party plugins that may be incompatable. It happened to me. I was able to edit but when I went to export, it froze. This was due to having Knoll lighting filters in the Adobe/Common/Plugin folder.
When I moved it to the AE plug folder, everything was okay.