This problem occurs due to two Bentley.PowerPlatform.FeatureAspects.dll in the mdlapps directory.

To avoid error message and crash, delete one of the Bentley.PowerPlatform.FeatureAspects.dll from mdlapps directory in the installation folder then restart Map.

C:\Program Files (x86)\Bentley\MapEnterprise V8i\MapEnterprise\mdlapps\