General Tips

1. Full Perms: Temporarily set your permissions to 777 on the path in question to see if this resolves the issue.
2. Owner/Group: Check the owner/group (chown command) of the PHP process for the correct permissions.
3. Suhosin extension:Check if the suhosin extension is enabled by checking the following areas:
   • WordPress Admin > Duplicator > Tools > General > Server Settings > PHP > Sushosin Extension
   • When running the installer see the installer-log.txt file

   If the extension is loaded contact your host or server admin and let them know you’re having permissions issues and you believe it might be related to thesuhosin extension. See if they can help you adjust the settings of the extension or turn it off.

4. SELinux: If Security Enhanced Linux is running on your server it may be possible that it is preventing even a 777 set from working. If changing thepermission and owner still has no effect then contact your host or server admin about the issue.
5. Help Videos:
   How to change your file permissions in cPanel
   How to change file and folder permissions using FileZilla

Root Folders

Some hosts prevent PHP from writing to the root folder of public_html directory. In this case you have a few options:

1. Contact your host and see if this is a restriction for PHP to write to your web servers root and if they allow a work-a-round. Some hosts will provide you with a custom directive specific to their environments. Some will allow you to change owner (chown) on the root via ssh. Check with your host to be sure.
2. If the root is off-limits then you will need to create sub-directory off of your root directory and place the installer and archive file in the sub-directory and run them from there.

Installer Tips

When the plugin archives a file from “System A” to “System B” it can retain the permissions such as “644” from “System A” to “System B”. If you wantto change the permissions on “System B” at install time them follow these instructions:

Duplicator Pro

1. Browse to the installer.php “Step 1 of 4: Extract Archive”
2. Under “Advanced Options” find the sections “Permissions”
3. Set the Directories/Files to the permission sequence such as “644” and check the checkbox
4. Click “Run Deployment” this will recursively set the permissions for Directories and Files
5. For individual directories/files login via FTP/SSH/cPanel and manually change the files.

Duplicator Lite

1. Open an FTP client such as Filezilla
2. On the folder where the installer.php is placed set all directories to “755”
3. Then set the files to the permission sequence such as “644”
4. Be sure to choose the recursive option

Note: If you still have issues temporarily try 777 on both files and directories, then be sure to change back. If 777 does not work then youwill need to change the owner (chown) of the directory where the installer files are and the installer and archive files as well.

Windows Permissions

1. Open Windows Explorer and locate the root folder that WordPress is installed in.
2. Right click this folder, select Properties and click the Security tab.
3. Choose Edit then Add. The following users must be added and given FULL ACCESS permissions: IUSR & IIS_IUSRS.
4. After completion change FULLACCESS back to standard configuration of IUSR & IIS_IUSRS for security

Popular Host Docs:[HostGator][GoDaddy][HostMonster][BlueHost]

Also see:
Permissions set to 777 and file stillnot writeable
How to change file Permissions with FTP clients like Filezilla