Does anyone know how to get mods to work with the Deluxe edition?

I've downloaded the 'Streamlined' mod from http://www.numantiangames.com/mods/ and placed it in 'Documents\My Games\Lords of Xulima\Mods'. When starting the game I go to the Mod Manger (top left hand corner) which says no mods activated. I open the manager and choose 'Streamlined' and it says that the game will need to be restarted but when it does the mods box still says no mods activated. I've tried this with the 'Hate Food' mod too with the same results. I know that the game is designed to only allow one mod to be used within a game but how do I get that one mod to work?

Thanks in advance :)

Thanks for the in-depth explanation, I followed them to the letter and got further on than I did before as the mod did save and validate (tried it on Hate Food as that was all I had to hand) but upon loading the mod the same thing happened where it says that the game will need to be restarted but when it does the mods box still says no mods activated.

Unfortunately, I'm just off out now but will try again tomorrow and let you know how I get on. I'm hoping I just did something wrong somewhere. Once again thanks for taking the time to help out :)

UPDATE: Well obviously I did something wrong somewhere yesterday - I've just retried and it works perfectly. Once again, many thanks for the detailed explanation :)

Great! Glad I could help.

So glad I found your post quickly. It worked perfectly for me as well.
I also wanted to add the exact wording that was used in doing the fix.

For my example, I'll use the "Hate Food mod".
Once unzipped, the mod will be named "Hate Food - Lords of Xulima Mod" in the Mods folder.
Then you try to 'Save & Validate' it, you'll get the error message as explained. Don't close the message.
Write down the folder name such as ..Lords of Xulima\Mods\HATEFOOD_B2239A71 in my case.
In the mods folder, click on the 'Hate Food - Lords of Xulima Mod' and choose make a copy in the same \Mods folder.
Now rename the copied folder to 'HATEFOOD_B2239A71' in my case, yours will be a different code.
Now close that error message box and do the 'Save & Validate' once again, which should give you...
the message box 'Correct! The Project has been validated successfully.'

Hope this helps to clarify it a little more for anyone else looking to install the mods.

PS. I'm using Windows 10 and have the annoying OneDrive folder stuff also to deal with, but it copies the changes across all the folders, so no need to do it in each folder location.
Playing the GoG Deluxe Edition of the game as well, not the Steam one.