Hi
I just installed teensyduino, only for it to start with error messages and rest of gui invisible. GUI elements only became visible when the mouse went over them.
Initial startup of teensduino:

Error Messages (screenshot taken after mouse on all gui elements to make them visible)

Prior to installing the teensyduino, the arduio ide started without these errors and all gui visible.
System Details:
Teensyduino version: 1.45
Arduino IDE version: 1.8.8
OS: Windows 10 home
Arduino Location: D:\additional apps\arduino-1.8.8
Arduino has portable folder setup see:
https://www.arduino.cc/en/Guide/PortableIDE
Teensyduino was installed with WIFI off and antivirus turned off
Teensy LC has not yet been inserted due to ide errors