Currently, we are working on a conversion of a large number of Mule 3 applications to Mule 4, which probably deserves a separate article for itself. After initial run of MMA (Mule Migration Assistant) and initial round of cleanup to get applications to build successfully from the command line, some applications fail to work properly within Anypoint Studio 7.7. What that means is that none of XML configurations would open. In fact, all files that have “Message Flow” or “Global Elements” fail with a very confusing error below.
The only way to fix that behavior was to remove Munit tests (tests were converted by MMA).
Note that such behavior is not observed in Anypoint Studio 7.6.