Diagnostic Tool Hangs at 0%

@KTaube @Bungle @chris001

You can set permissions to the Suitecrm folder again and delete folder Diagnostic from cache.

sudo chown -R www-data:www-data .
sudo chmod -R 755 .
sudo chmod -R 775 cache custom modules themes data upload
sudo chmod 775 config_override.php 2>/dev/null

Also, run Quick Repair and Rebuild once and try.

Another solution is as below.

I hope this will work.