Also, which version of PAR::Packer are you using and did they use?

A packed executable is just a zip archive. If you unzip it you will find a META.yml file at the top directory that states both the PAR and the PAR::Packer versions.

e.g.:

build_requires: {}
conflicts: {}
dist_name: C:\some\path\where\the\file\was\built\parname.exe
distribution_type: par
dynamic_config: 0
generated_by: 'PAR::Packer version 1.039'
license: unknown
par:
  clean: 0
  signature: ''
  verbatim: 0
  version: 1.015
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