Warning: The PHP temporary folder is not set.

AzimuthDesigns

How serious is this and what should I do or repair to have this warning resolved?

saguaros

The PHP temporary directory is the directory that PHP uses to store an uploaded file before Joomla! can access this file. Whilst the directory not being set isn’t always a problem, if you are having issues with manifest files not being detected or uploaded files not being detected.

If you don't have permission to edit php.ini file on your server side, you can contact your hosting provider for help to adjust the upload_tmp_dir setting in your php.ini file for you

It will be fine then.

AzimuthDesigns

It's very peculiar error warning.
Joomla is using the correct folder for uploads and it's full of extensions, plugins that I've been installing.
php.ini points to the correct tmp folder with the correct permissions of 755.

I've always seen this error on my joomla sites over the last 7 years. I'd just love to be able to have an error free admin panel for when my clients go into their websites!

saguaros

AzimuthDesigns Could you try to contact your hosting provider for help to check the permissions?