Annoying message when workbook Opens

[AlexanderBB]

This application is about to initialize ActiveX controls that might be unsafe. If you trust the source of this file, select OK and the controls will be initialized using your current workspace settings.

Googling this was a nightmare, way too much info for simple fix. I have set what looks like the right things in the Trust Center settings and also added the folder into Trusted locations. Nothings changed.
I don't normally see this and suspect it might have happened after adding a rich text box. This shows under References as Control 6.0 (SP6) C:\WINDOWS\system32\RICHTX32.OCX

Can i get rid of the prompt? It wants an OK every time.

 

[Micron]

Fairly certain it is not enough to put the wb in a trusted location. You went to these settings as well?

 

[AlexanderBB]

Yes, I did. The selected bullet is the last one. Enable all without.....
I don't have a tick in safe mode though.

 

[Micron]

Sorry, then I'm out of ideas.

 

[AlexanderBB]

I'll keep digging around and leave the solution here if I find one.