You may have gotten it right by putting names into the unused filter slots. I had a conversation with Colin at Diffraction yesterday (far more efficient than writing in the forum). He suggested adding the names back nto the unused filter slots, calling them Unused2 Unused3, etc (to help diagnosis). With names in the slots, he thinks the numbers in the list and the number used for direct filter selection and reading will match up, avoiding that problem with index out of range etc. The downside is that the lists of filters on the web UI will contain all of those Unused entries. Give it a try. Not a long term solution but it could get you going.