CustomMaskAssembly
Path of the DLL file which contains the assembly that displays a metadata entry mask. This mask is used when saving entries to DPE (this happens when the editor was called from Content Manager), or when bulk saving more than one entry to DBM.

Starting with MTE/ETE/STE version 8.5.1884.0, if the file specified is a 32-bit DLL, the editor attempts to use a file with the same name, but "64" appended. For example, when MteDefaultCustomMask.dll is configured and this is a 32-bit DLL, then the program tries to use MteDefaultCustomMask64.dll instead.

Starting with editor version 8.5.1885.0, Only file name and extension are required if the file is stored in the same directory as the editor's EXE file.
Possible values:
Default value: MteDefaultCustomMask.dll