UE4 won't let me rename my materials

What is your Build and project directory? unfortunately if you have a really long project name and many folders within folders you can run into this. What if you try shortening the parent folder names to see if it lets you enter in that many more characters?

I can type anything, even just one letter and a warning comes up saying something like i can’t exceed so many characters (i think its in the hundreds) and I am just left with NewMaterial1,2,3 etc which could be quite hard to distinguish when I create more. I only have around 9 atm so i can tell them apart by the sphere but it is still annoying. I’ve tried renaming them afterwards and i get the same error.