in reply to Running a perl 5.8.6 CentOS 6-compiled app on a CentOS 8 platform
I think that the biggest thing to determine now is that the entire execution environment is exactly as it was before: the Perl interpreter version, and, most especially, PERL5LIB and all of its consequences.
"The immediate problem here now being," of course, that the application as installed might well have referenced any number of Perl libraries from the then-existing "system-wide environment." And, in like manner, the software could still be doing the same ... the problem now being that the system environment has now changed.
"Containers" are an excellent path forward here, at least on the short term, because with them you can re-create the environment that this application expects to see, in an "actual" environment that is by now much different. This should at least enable you to stabilize your situation. (And, if need be, to actually run it indefinitely.)