Trouble naming a cloned copy of "sandbox plugin"

I've managed to get what I wanted working, I copy pasted the "sandbox plugin" and renamed it to "Test and test" everywhere that "Sandbox and sandbox" was listed which worked for my testing, but when I try to change the name to anything meaningful it doesn't work, has anybody found this error before or have a solution perhaps??

Maybe I also need to change something else somewhere?

Regards,
Patrick.