I am having more issues with the plugin and I think it may be OpenGL again. I do not know which of the last 1.1.x updates was the last working one for me, but I believe it was 1.1.3.
What is the current requirement for OpenGL version?
I have an excerpt from the log.txt below, your last response and fix, and more system information. The full log.txt is atached.
2019-02-22 23:34:31 TBM900[shader.c:405]: Cannot load shader /home/ryan/Games/X-Plane 11//Aircraft/X-Aviation/TBM-900/plugins/systems/data/libsvs_shaders/generic.vert.glsl: compile error: 0:5(12): error: extension `GL_EXT_gpu_shader4' unsupported in vertex shader
2019-02-22 23:34:31 TBM900[xplane.c:1453]: Systems plugin is disabling
$ glxinfo | grep OpenGL
OpenGL vendor string: X.Org
OpenGL renderer string: Radeon RX 580 Series (POLARIS10, DRM 3.23.0, 4.15.0-45-generic, LLVM 7.0.0)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 18.3.3
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 4.5 (Compatibility Profile) Mesa 18.3.3
OpenGL shading language version string: 4.50
OpenGL context flags: (none)
OpenGL profile mask: compatibility profile
OpenGL ES profile version string: OpenGL ES 3.2 Mesa 18.3.3
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20
OpenGL ES profile extensions: