Created attachment 6086 [details] [review] remove duplicate PDF::Reuse initialization on koha 3.0.6, labels/label-print-pdf.pl appears to mistakenly initialize PDF::Reuse twice (by invoking prInitVars() and prFile() in two different places). This causes the output pdf file to always be broken (try passing it to pdfinfo from poppler-utils). The attached patch should resolve the issue.
3.0 is quite old at this point and label-print-pdf.pl is long since removed. I would recommend upgrading to the most recent stable release 3.6.0.