Yes, me too. The folders seem to be set up ok and the ptf file is definitely there, but it can't find it for some reason. This post is a few months old now, so did you resolve this?
Ok, with some help from David at EPC HQ I inadvertently solved my problem:
At his suggestion I clicked on Default.ptf and then on Edit, to see if that reported the error. It did not. Then, having cleared that tab I found that New Item and Wizard in PCB symbols worked and has continued to do so!
No idea why it did this but at least it's stopped now. Onwards and upwards!