Recently, I upgraded my android studio to 4.2.1. Then I found all of my projects are not working, I got this erro rnavigation.json (The system cannot find the path specified). Even I created a blank activity project, I got the same error. Therefore, somethings. I tried to switch to lower sdk version, that is still not working. Finally, I found out I put my project in an external disk which is using ex3 format. So that, I can use it in my pc and mac. Is the disk format causing problems? Then I moved my project to the main disk which is using NTFS. Then that is no problems, strange