The error appears when the DFA and/or MAT files in the project folder have become corrupt which can result in blank material layers.
First, hold down Esc key to get through all the errors. If you don’t have a backup to revert to (always the best option) then we recommend assigning the default construction to each category. To do this open Assign Constructions and assign the default construction to each category.
Save the corrupt project and then create a new one by selecting File>New
and name it default constructions.
Now go to the folder the projects are saved to
Open the corrupt project folder and also the default one you just created so they are side by side and browse to the Apache folder in each of them.
Delete the DFA and MAT files from the corrupt construction project. Next, copy the DFA and MAT files from the default constructions project and paste them into the Apache folder in the corrupt project.
Right click on the DFA file and select Rename.
And rename it so it has the EXACT same name as the project. Do the same for the MAT file.
The default constructions should now be assigned and you will no longer get the errors when entering VE Compliance.