Toggle key not defined?

I installed Reshade 3.1.1 with Lord of the Rings Online and worked fine. However, the Scroll Lock key doesn't do anything when I want to switch back to the original graphics -- I've seen conversations from lots of LotRO users, all years old, which say Scroll Lock works fine.

I found an old thread (click here) which said if it's not defined then you can define it yourself in reshade.fx . But I can't find reshade.fx! I can find reshade.fxh, but from the content it doesn't look like the place to make the edit.

Can anyone help me set up the toggle?

In-game menu (Shift F2) > Settings > Effects toggle key.

Ah thanks, I overlooked that. However, once set, it still doesn't seem to be doing anything - reshade is always active. I don't think Scroll Lock is being used by my game to cause any conflict but just in case, I tried the Pause key and it also didn't work. I was in Performance mode so I tried switching back to...uh...configuration mode? But made no difference. Any idea why the defined key might not work?