I’ve struggled for weeks trying to install KiCad, plus open and save files. Every tip I read on this forum failed for me until this morning I came upon this post: KiCad cannot save or create files - #16 by Efcis
The issue for me, running WIn 11, was Windows Defender blocking KiCad. Once I followed the simple steps in this post everything worked perfectly. Thank you to the poste! You made my day!