Description
You may see the error "Can't turn on the open-drain option for differential I/O pin" when running the compilation process at the Intel® Quartus® Prime Compiler Fitter stage.
The error can be caused by changing the data width in the IP of the existing design.
The changes may apply to the IP only, and the top-level design file still has the previous value.
Resolution
To fix the error, ensure the top-level design file has a similar port width to the IP file.