Hello,
I believe it should be fixed once and for all unless some changes were being made using FTP which may cause the installation to stall as it wouldn't be able to overwrite files.
To give you a glimpse of what actually happens when you modify the file with ftp:
1. When you install EasyDiscuss, often the webserver user is storing those files (Most likely "apache")
2. When you modify files on EasyDiscuss with FTP (depending on your web host), these files are automatically changed to your FTP user. Or if you created some new files in these directories.
3. When you try to upgrade, the user "apache" wouldn't be able to overwrite files from these directories and caused 500 errors.
Would this be clearer for you now?