Awesome! This fixed my issues as well.

I am having the exact same issue (only it was beta 2). I've cleared and reinstalled 16.4 and that did not fix the issue. I still cannot create any simulators. 18.5 shows up as mounted in Disk Utility but I get the same output from simctl list as chandler.dea. The other part of this for me is that I cannot run most of my apps on my iPad (running 18.5). I get the following errors: Assets.xcassets: No available simulator runtimes for platform iphonesimulator. SimServiceContext supportedRuntimes=[SimRuntime : iOS 18.5 (18.5 - 22F77) - com.apple.CoreSimulator.SimRuntime.iOS-18-5 (unavailable, liblaunch_sim.dylib could not be opened)] LaunchScreen.storyboard: iOS 18.5 Platform Not Installed. This has already cost me a number of hours and I am unable to do any development until this is resolved.

Submitted a new beta build yesterday and am seeing the same issue. The app wasn’t showing up in TestFlight, so I deleted my email from the ‘All’ list of testers and then added it back to the internal list. Clicking on the invite produces the error message ‘TestFlight is currently unavailable. Please try again later.’ This appears to be an issue with my phone, because others on the development team have been able to install with no issues.