The user has an STL file from which is not possible to create a mesh. The error occurs: changes cannot be applied to mesh as it has faults.
Solution
It is best practice to check the geometry of the part using Geometry Inspector and remove any faults.
In Solid Edge 2020 you will have a new function to delete faulty facets under the Mesh Body Healing options.
Then you will be able to create the correct mesh of the Body.
I
Hardware/Software Configuration
Platform: all
OS: n/a
OS Version: n/a
Product: SOLID_EDGE
Application: PART/SHEETMETAL
Version: V219MP6
Function: REVERSE_ENGR
Ref: 002-8014192