So I decided to work on my game again and suddenly, it would not save. What I did is just change the window size, and when I tried saving it, it says “Unable to save the project! Please use a different location.” I can’t save it to another location because the save as button is greyed out. I wasn’t working with the grid/mask on and I tried moving the project to another location but it is still the same. Please help. Thanks! 
Where is your project saved on your computer?
maybe it is a permissions problem from your operating system?