Beta 5 of X-Plane 12 Early Access is available on Steam & through the Laminar Research installer. You should be prompted to auto update the next time you launch the sim, if you haven’t already. Here is a link to Early Access release notes.
This build contains a fix for the crash at start many of you reported in beta 4. So again, if you are still seeing it, let us know by filing or re-filing a bug. Windows users should include their email in the crash report so we can find your specific crash. Mac users should send the Apple crash log with their report. We are actively working on restoring auto crash reporting on Linux.
We’ve heard a lot of reports that Steam users on Linux have been unable to launch the sim since beta 4, and beta 5 is no different unfortunately. We are investigating with Steam now.