WordPress can update its core and plugins directly from the administration area, but the process needs permission to write temporary files and replace application directories. On some IIS or cPanel environments, an automatic update fails with the message ‘Download failed. Could not open handle for fopen()’.
Why the fopen error appears
The updater cannot create or open the file it downloaded. The most common causes are incorrect ownership, restrictive permissions on wp-content or wp-includes, an unwritable temporary directory, or a hosting rule that blocks the web process from writing. FTP credentials can be correct while the underlying filesystem permission still prevents the update.
Check permissions and ownership
Confirm that WordPress directories are readable and writable by the account used by the web server. On many Linux hosts, directories use 755 and files use 644, but ownership is just as important as the numeric mode. Do not apply broad 777 permissions as a permanent solution.
On IIS, grant the application-pool identity the minimum modify permission required for the WordPress installation and temporary directory. Take a backup before changing permissions, then retry one plugin update and remove any access that is no longer needed.
Validate the result
After the update succeeds, confirm the site loads, the plugin is active and the error log contains no new filesystem warnings. If the host manages permissions centrally, ask support to correct ownership rather than repeatedly changing modes from the WordPress dashboard.
