Description
When opening certain .ptb files I get an error of this kind "Error opening file: vector::_M_range_check: __n (which is 18446744073709551615) >= this->size() (which is 27)"

To Reproduce
I get this error with the ptb of "Oblivion Ocean" by Pain of Salvation downloaded here: https://tabs.ultimate-guitar.com/tab/pain-of-salvation/oblivion-ocean-power-309086

Version
Debian 11.5 (Bullseye). Power Tab Editor 2.0 Beta (v2.0.0-alpha15-2-g9a6e645f)