I had the same problem in my comments. In my case it was a custom code snippet that I had added for Objective C, but I had it set as All Languages and at all levels. I changed my code snippets properties and now I don't have that annoying popup whenever I'm writing comments. I'm guessing that Nimble created a code snippet and it doesn't have the correct properties so that it shows up at all times, even in comments. Type Shift + CMD + L and see if you can find that expect code snippet and fix or remove it.