I have a similar problem! Today I searched for new updates and there was an update for the edain core. I pressed "update" and at some points (while the download of the date was in progress) I get the messages "Edain_Mod_Launcher - Error renaming patch files" and "Edain_Mod_Launcher - Error renaming patch files 2". Although, the update process was completed, I am not able to read any "description text" on units, building, spells, heroes etc. in the game, I can only read their names. Also I do not know wether the game was really updated... everything looks the same.
The only thing I did I think was to try the original Rise of the Witch-king via the Edain Launcher. I did not move or touch any file anywhere. I was also puzzled about the "Auto-update" function, while the box it is ticked, from times to times I check manually for new updates and this time I found new stuff.
Please help me, I really find your work a masterpiece and I enjoy it everytime I play.
P.S. Sorry for my english