@BananaBombFilms
Here is not the place to ask about modding, EA doesn't support modding and discourages their use. However you can mod the game if you're playing offline, and if you do it online you may never get penalised if it doesn't trigger their bots. No mod is 100% safe, and EA/DICE updates their bots from time to time so mods that used to work just fine may start getting people banned "out of nowhere".
I suggest you search for modding communities and ask this there. One that I'm familiar with is the BFII modding Discord. If you want an invite to it, please DM me here and I shall provide it to you.
What I can already tell you to maybe solve your issue is the following:
- If you started using mods just fine, and then the game suffered a client update (a.k.a. you had to download a patch for it), then you must go to the directory where the game is installed and delete the Mod Data folder;
- If your Frosty Mod Manager's version is older then the one your mod(s) were created with, it won't work at all. Be sure to be using the latest version of Frosty Mod Manager;
- Try checking if it isn't an issue with a single mod itself. I can share with you a few mods I know work in the latest Frosty Mod Manager version for testing. DM me so I can send them to you (or tell you where you can download them);
For further info on this, I prefer we exchange DMs about it, because this topic isn't welcome in EA forums.