Use TESVSnip to convert the .esm to .esp
1. Load the .esp in TesVSnip
2. Save the .esp as .esm with TesVSnip
3. Load the converted .esm as an active file in CreationKit
4. Open actor window for one of the actors and click Okay (no need to make changes)
5. Save. It is now a master file.
And yea the point of this workaround is to convert the esp to ESM MASTER FILE.
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And for those who are playing with custom companions using the .esm technique,
When I exit the game and load my save the companions that were following me are back at their default location and I have to re-invite them to my party,
Anyone with this issue?