A bug in KAPK which is not letting the users to download wallpaper from widget packs. It says"Unable to create directory"

There is a bug in KAPK which is not letting the users to download wallpaper from widget packs. It says Unable to create directory. This issue was reported by me 8 months ago for which the developer replied that he will look into it but unfortunately the issue is still not solved. kindly look into it seriously. People are getting mad and giving 1 star to my apps. What can I do about this issue? Is it my fault? People don't seem to understand the issue and getting 1star and poor reviews are the worst nightmare a dev can have. Solve this issue ASAP.Reddit post I made 8 months ago.