Operating system:Windows7 Home Premium 64bit
Graphics card:NVIDIA Quadro K600
Broken: (example: 2.80, edbf15d3c044, master, 2018-11-28, as found on the splash screen) 2.81
Short description of error
After upgrading from version 2.80 to 2.81, there was a problem that part of the texture of the model disappeared when opening the file.
There was also a bug that the add-on was checked but could not be converted to FBX format.
Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).
Occurs after updating to 2.81.