Trouble launching client after clearing cashes (solution)

If you can't launch the client after you just cleared the cashes, do this:

First clear the cashes again as i assume you've messed around a bit before.
Then, exit MCreator and open up a new instance, create a new workspace and title it whatever you want.
Now exit MCreator yet again.
Open up the old Workspace and navigate to the Build & Run tab at the top of the workspace.
Now press the following buttons in this order.
Build Workspace - Reload Gradle project - Regenerate code and Build

This should fix the problem, idk why. But it does.