which mods? What's the exact path that the dcx files are being placed in? What specifically do you mean by "haven't worked"?

(Edit: other comments didn't load, glad you figured it out 👍)

They need to go in subfolders depending on the asset they are replacing.

For example, a sword or armour or whatever would be a "parts" file, so it would go in /modengine2/mod/parts/[file].dcx

If the dcx file came in folders like /cool hat/green/[file].dcx and /cool hat/blue/[file].dcx, then you need to pick just the dcx file you want to use, and ignore the alternative versions.