I have problems in upgrading a site from J4.1.6 to J4.2.6, and I get an error message saying that Joomla cannot communicate with the file administrator/components/com_joomlaupdate/extract.php. I have been informed that I should disable Admin Tools and reset the htaccess file to default. However, this caused that I get "No input file specified" both in frontend and backend.
I have now uploaded a backup using Kickstart, but when I reached the Clean Up step nothing happened even though I pressed the button several times. When refreshing the screen, I have now been locked out of backend. I thus went to the file manager in order to diable Admin Tools, but in the plugins/system/admintools folder there is no admintools folder and no mail.php file.
What do I do now? How do I disable or install Admin Tools so I can access the site again?