If you look in your .minecraft/mods folder, you should have a dungeons sub-folder listed and within it, a plans sub-folder that has many .json files in it. If you don't have these folders nor have the .json files, then you didn' install the mod correctly.
Posting in this thread because you have so many different threads for your dependency mods, and this is the one most recently posted in. I hope that's cool.
I'm currently trying to run Dungeons! in 1.8 with PlansCreator so I can create plans and then bring them into Dungeons! 1.10.2. Unfortunately, I've run into a strange issue. When trying to run all the latest versions of the required mods in 1.8, I get an error during launch saying it can't find PlansAPI. I then tried downgrading to an older version of PlansAPI (4.0.4) and that doesn't fix the issue; it just says it requires 4.0.8. However, again, when i run it with 4.0.8, Forge throws up the error that it can't find PlansAPI. I'm at a loss as to why it's doing this, but it seems PlansAPI is not loading properly?
My /mods/ folder looks like this:
It looks to me like I've installed and unzipped everything correctly, so I've no idea what to do. Any help would be appreciated! Thanks!
(As a side note: it would be absolutely swell if you were to update PlansCreator to 1.10.2 and upload your mods to curseforge. Dungeons! has massive potential combined with the functionality of PlansCreator for modpack creators and could honestly gain a lot of popularity there. Dungeons2! looks good, but its simplification from the original mod makes it less powerful insofar as creating custom dungeons for modpacks.)
What version of Forge are you using (full version). I tried with an older version - 1.8-Forge126.96.36.1997 and I got the same error that you describe. But I also tried with a later version 1.8-forge1.8-188.8.131.523 and it worked fine.