Every time I log on my mac asks me messages agent wants to use my keychain, How can I get rid of it?

I've tried everything suggested here. All the boxes are correctly checked or unchecked, I cannot find a keychain/library folder with any series of letters/numbers in it. Still having the same problem.

Hi,

I am having the same issue. Can you please help?

Thanks

This is maddening... Messages just will not stop. 😠

"From the menu bar, select

Keychain Access ▹ Preferences ▹ First Aid"

Apparently this no longer exists. (Running El Capitan, 10.11.6)

Is there any other way to access / run Keychain First Aid?...