- If possible run cron and clear caches (1-9) with Drush
- Change of PHP version to match the Drupal version used. For older Drupal 7 versions possibly downgrade to PHP 5.6. For Drupal 8 possibly upgrade to PHP 7.0 +
- Increase PHP Memory limit to at least 256M
- Copying of original .htaccess and settings.php from Drupal installation. Disable/Remove to see if it is the cause of the problem.
- Check-up and correction of user rights, 755 and 440 special files
- Run update.php (set TRUE for free acess in /sites/default/settings.php, go to www.domain.xxx/update.php and follow the instructions)
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