My problem is odd. I have set up the webcollab on my server where I have my website that works well with php and mySQL. While adding webcollab onto this server, I edited the config.php as your instruction. However, it shows "unable to connect to database." I tried to change mySQL_PDO into mySQL. It shows the error clearly. Because I used the existing database instead of creating a new one, I think I might change some codes for that. Please let me know how to solve this problem. Thank you very much!