Beta 15 is fully supported by GSX, which is all that we are using for the past month or so. But we can't guarantee that you a starting GSX from a 3rd party toolbar would work.
Also, the Toolbar menu and the Couatl engine are completely unrelated with one another. An issue with the menu cannot affect the Couatl engine, and vice-versa, anything that could possibly happen with the Couatl engine cannot possibly affect the menu so, according to your report, you are probably having two separate problems at once, which we can't replicate to be happening so no, it's not the Beta, unless you had issues with something like an incomplete installation of the Beta itself.
As usual, once you verified that:
- The Addon Manager folder is added to the antivirus Exclusions
- You are on the latest GSX Update.
There's not much else left to say, considering you haven't reported of any visible errors or posted any startup log, which is the first thing to do when reporting a problem.
The only thing I can confirm: no issues whatsoever with Beta 15.
