Description
Invalid entities are faces or curves with geometrical problems which prevent most operations like Split or Trim from working properly.
Recommendation
It is highly recommended to try and fix all the invalid entities using the Check & Fix Entities tool.
Unsolved Cases
If the Check & Fix Entities tool fails to fix a problematic entity and this entity is required for CAD operations (for example Split or Trim), it is recommended to remove the original entity and recreate it manually.