[otrs-de] IO::Handle: bad open mode: <:

[Udo Giacomozzi]

Hello,

I just upgraded from v2.0 to 2.2.4. OTRS is mostly working again now,
but I'm having problems with PostMasterPOP3.pl which is aborting with
this error message:

  IO::Handle: bad open mode: <: at /opt/otrs/Kernel/cpan-lib/MIME/Parser.pm line 1136

I don't speak Perl, but I tried to replace the line

  $io = IO::File->new(\$data, '<:');

with

  $io = IO::File->new(\$data, 'r');

But then the file does not seem to be opened because then it complains
about "isa" not being defined or something like that.

Any suggestions? What is open mode is "<:" and what mode would work on
my system?

System is Red Hat Linux 8 (Psyche). Perl is v5.8.0

Thanks,
Udo