The file /home/ilovetape/domains/ilovetape.nl/public_html/pivotx/db/ser_tags.php could not be written!
Try logging in with your ftp-client and check to see if it is chmodded to be readable by the webuser (ie: 777 or 766, depending on the setup of your server).
Current path: /home/ilovetape/domains/ilovetape.nl/public_html/pivotx.