What are you trying to do, and what do you expect to happen? I didn't open Blockbench for some months and now i can't edit pbr materials for java anymore. Pretty sure I was able to do it before. This ...

What are you trying to do, and what do you expect to happen? After creating a texture or java block/item model, and clicking save, or going to "File->Save Project" & selecting a valid folder and file ...