I've developed a custom plugin for WP. When I install it manually on my server, using FTP transfer, all is perfectly working. I tried to make a zip file and uploading it through WP admin panel. All seems to go well, but when I try to use it I get many 500 errors, due to the permissions given to my plugin's files by WP. Folders have 755 permission and files have 644 permission. I read that these are the correct permissions for WP, but in this way when a file situated in a subfolder is called via ajax, I get a 500 error as this file hasn't execute permission (644). Giving to my file manually 755 permission makes it work. What can I do to make WP give the execute permissions to my files when installing the plugin using the zip file? Thank you.