Upgrading Drupal

I have a site that has been running for about 10 years. I think it was Drupal 6. It was hacked up pretty good, and although I have *some* proficiency, it's been a long long time since I developed. 

The site finally completely broke, and I am unable to get into the UI. Homepage returns a 500 error. Nothing has changed on the site for at least 5 years.  I traced it down, and it looks like it is failing on a syntax error from mysql. It looks like something was changed or deprecated between mysql, and the database functions.

 but when i start Download any module in Drupal 8 give me memory err infect i  increase memory in php.ini file 2G memory limit

i try  many solution but still i face this issue

I had been using 9.4.9 and upgraded to 9.5.11. In response to the warning about CKEditor being deprecated, I followed the instructions as follows:

Hello,

I am upgrading yet another older site from 9.5 to d10 and the composer update seems to go smoothly until extracting/installing the Drush 12 archive and then I get this error:

In FilesystemRepository.php line 163:

file_get_contents(/var/www/html/mysite/vendor/composer/composer/src/Composer/Repository/../InstalledVersions.ph
p): Failed to open stream: No such file or directory

Hi Guys,

I had upgraded my Drupal version from 7.69 to 7.94.
After upgrading my custom pages are not loading and throwing this error: 

: Maximum execution time of 300 seconds exceeded in on line

Fatal errorC:\xampp\htdocs\hg_hpbx_d7\misc\typo3\phar-stream-wrapper\src\PharStreamWrapper.php408

I had also tried to increase execution time in php.ini but nothing works.

I'm encountering an issue during my Drupal upgrade process, specifically when I updated the Barrio Bootstrap 5 Theme Module from version 5.5.4 to 5.5.13. The problem I'm facing is that after the update, all the buttons with the class "btn btn-primary" are automatically being transformed to "btn btn-" and are missing the "primary" class, causing them to appear as plain text instead of buttons. I need assistance in resolving this issue related to the module upgrade.