How can I change Minecraft Version of a modpack? I found a modpack called "Speed of Light FPS Booster (SOL) that changes versions, so I know it is possible to release a modpack for different versions. How can I change Minecraft versions of a modpack?
It's basically a new modpack each time. For each mod in the old modpack, use the new MC version of it, if it exists. Sometimes they don't exist or they may not be compatible anymore, so it's not always easy.
The only way to change the mc version of a pack is to recreate the pack from the beginning. Once a custom profile is created you cannot change the mc version. You can only update/downgrade the modloaders version as well as the mod versions for that mc version.
This is designed like this for a reason as not all mods are compatible when the mc versions change. Just because they "should be" doesn't mean they will be.