If the "unsupported modified version of Minecraft" error keeps appearing when using your Minecraft mod, you might be dealing with an incompatibility problem. Uninstall the mod, and try and download a different version of it.
But also, the issue can be due to your mod not having enough memory. On CurseForge, you just go to the MyMod Pack section, find your modification, and then go through the latest updates for it (more on this later).
A few weeks ago, I actually got stuck with the unsupported modified version error. Although I was surprised at first, I've heard how outdated mods can cause the issue. And I knew that I probably was using an older version, so I updated it and this fixed it immediately.
I not only ran through how I did this but all the other ways to get rid of the "using an unsupported modified version of the game" issue. Let's get to it.
There are a few different ways to get rid of the error message, and I've run through them with the solutions provided ahead.
Minecraft has a bunch of different mods out there. Unfortunately for you, you may have downloaded one that your device can't handle. If the crash report message popped up for the first time after you opened the modpack, then it not being compatible probably is the culprit. Go ahead and uninstall it, then look for another version to download.
Remember to carefully go through the new mod's specs sheet, and then compare this information with your computer's. Here's a useful guide on how to find your computer's data on Mac and Windows.
Here's how you do this on Windows:
Here's how you do this on Mac:
Your Minecraft mod might not be compatible with your vanilla Minecraft version. When there are compatibility issues, you end up facing all kinds of problems, like random crashes, loading issues, and even the unsupported modified version error.
Depending on the Minecraft launcher you're using, the specific process to update your mod will defer. I've run through how you can use my personal favorite, CurseForge, below.
Here's what you do:
Some Minecraft mods, like the one that you've downloaded, can require more memory than what was given. If this is why you're dealing with the issue, you don't have to do much to fix it. Just try and dedicate more space to Minecraft and its resource packs and see whether this helps.
Now, the process to follow will differ depending on your launcher. Here's what you do on CurseForge:
Just like Minecraft needs Java to work, this is also the case with its mods. To try and fix the "using an unsupported modified" error, you can try updating Java.
Here's how you do this:
You can get stuck with the "the different version of the game" error for a few reasons. And usually, it pops up because your mod is outdated. I ran through how to update and get rid of 'using an unsupported modified version of the game" on CurseForge.
Also, the problem can be due to you not dedicating enough memory to Minecraft, or because you're using an outdated type of Java. I've touched on how to fix this too.
Hopefully, you found all the solutions that were discussed in my post useful.