I am using FoundryVTT Version 12 Stable 331, and there are no other modules enabled in this.
I think this might be related to you having a version of the module higher than you should be able to. It’s something I fixed now, but there was a window where you could install the Foundry v13 version of Terminal in Foundry v12.
If I’m right on this then you will need to just uninstall and reinstall the module. This is completely safe to do.
When you reinstall it should download 3.2.6 for you. Let me know if that fixes the issue for you.