On editing anything in OpenType Layout Feature Code Editor - OTLFD, it returns the error Failed to compile the code.
For your reference, screenshots have been attached.
In the screenshot, you see that in Line.#.2442 entry is NULL
if I changed NULL to value 0 then it’s ignored otherwise it returns an error.
Line #2442 is just a warning, so it should compile, but the error is the empty lookup at #4855. It should compile after you have removed that lookup.
Can you edit and compile with the Adobe feature syntax (FEA) instead of OTLFD? That is nowadays the preferred syntax.
No, I am just using OTLFD
okay, I’ll remove the empty lookup.
Better use the upper-left combo box to switch from OTLFD to FEA.