broken Taxonomy

Dear Drupal experts,

We are a group of concerned individuals, that seek to help the worlds tribal peoples. We work to protect their human rights, environments and cultures. In Germany we are registered as an e. V. organisation (not-for-profit). See: www.naturvoelker.org but our interCultural site: www.fPcN-global.org is where we need to help. A volunteer, offering to upgrade from 4.7 to 5.5 got in to a real mess and was unable to complete the task in anything like a reasonable time, leaving us off line and with a disabled site for months.