Perl Errors After Server Upgrade

[orcahouse]

We are still running Sellerdeck 11.0.6 - yes, I know but it has served us well. We have been hosted by eUKhost for many years with only the occasional problem but they have now migrated us to a new server running Perl 5.16.3. There have been a few issues mostly resolved but we are left with 2 major ones:

We are not getting callbacks from Sellerdeck payments to generate the .OCC file.
The real time stock update is not functioning and generating an error when we download orders. See attached.
Nothing has changed our end and CGI permissions are all 755. I have changed script numbers and refreshed but no change.
They say we have to update our website scripts to make them compatible with the new Perl version. Does this sound the likely problem?

[brucet]

If you haven't already done so, I think you will need to contact Support about that

[orcahouse]

Thanks Bruce. Unfortunately we don't have a contract and I'm not sure v11 is supported any more.
For some reason we are now getting callbacks and payment confirmation. Hosts deny all knowledge of changes at their end!!
Main error from the error.log is:

failure cleaning transaction file (An error occurred while creating the stock transaction lock file (../acatalog/stocktrans_lck.fil). The error was Permission denied.)

Permissions on CGI-Bin are 755 throughout. Acatalog is 777 but the majority of files in the folder are 644. Could this be the problem?

[brucet]

I really don't know, sorry. I don't know a lot about server-side issues