Bit of an edge case but something I ran across.
When running Ardour with X11 Forwarding (IndirectGLX on) plugins using the JUCE framework crash Ardour when loaded into a session.
The program 'ardour-6.6.157' received an X Window System error. This probably reflects a bug in the program. The error was 'BadRequest (invalid request code or no such operation)'. (Details: serial 58 error_code 1 request_code 130 minor_code 2) (Note to programmers: normally, X errors are reported asynchronously; that is, you will receive the error a while after causing it. To debug your program, run it with the --sync command line option to change this behavior. You can then get a meaningful backtrace from your debugger if you break on the gdk_x_error() function.) Cannot write socket fd = 29 err = Broken pipe
Tested with Sonobus VST3 and Squeezer LV2 & VST2 using Ardour-6.5.0 (official) and a nightly build.
Both of these plugins load correctly when Carla is used as the plugin host.
I don’t know if it’s worth looking into but thought i would bring it up on the off chance someone knows of a workaround.