Using arduino 2.3.4 and teensy 1.59
I deleted the files in C:\Users\<username>\AppData\Local\arduino\sketches\6DDFA74DF6067593195A812337EE5AD7\pch
and C:\Users\<username>\AppData\Local\Temp\arduino-language-server549245311\build\pch
The files causing problems are the precompiled header files...