Without checking I am just going to assume that you used the latest forge version and renamed the universal file. Forge made changes to newer versions, which includes the latest versions for 1.12.2, where you have to instead download the installer and rename that to modpack.jar. Lots of users have been having this issue recently as forge seems to have "snuck" these changes into the latest 1.12.2 builds, previously they were only for 1.13+, hence why any guide you may have followed did not include this newer info.
If that's not the case then I will take a closer look.
Literally fixed my issue. Made this account just to say thank you. Been doing this on occasion for over 5 years; never seen this before, but it's 100% what needed to be done
Forge not installing?
in Platform Pagoda
Posted
Literally fixed my issue. Made this account just to say thank you. Been doing this on occasion for over 5 years; never seen this before, but it's 100% what needed to be done