WordPress Update Failed: Could not copy file. also known as “could not create file or directory”. Mostly this error has two reasons.
1- If your localhost running on a Windows, there could be a bug between the WordPress updating system and Windows hosting setting.
2- If the server your are using which is not Windows based and some of the file/folder permissions are not allowed by the host/administrator. Contact your host provider to make sure that file permissions are allowed to upload/remove/change files on server through WordPress or FTP.
How to fix update failed could not copy file error:
1- This error is mainly due to the file permissions setting on your server. Try to delete the plugin and install it again. You won’t lose any of your settings this way. It’s like same process when update plugin from Dashboard.
2- Sometimes this error occurres due to not enough disk space or reached max files in the web hosting account. Check on the available space in c-panel because WordPress needs enough space to download the plugin, unzip it, and then move the files across.