[Koha] Import of .KOC file into Koha 17.11 hangs

[Chris Brown]

Hello,

Using a fresh install of Koha 17.11.00 (from Debian packages) I have
successfully loaded our patron data, our catalog and our items. However
when I try to import an offline circulation (.koc) file, nothing happens.
The progress bar sits at 0% and nothing is imported.

In the past I have successfully imported a .koc file with an identical
format into Koha 17.05.

Has the .koc file format changed for 17.11 perhaps? Is there some way to
get a more detailed view of what is (or isn't) happening?

In case it helps, here are the first few lines from the file:

Version=1.0
2016-03-30 12:00:00 000 issue 000785874 1353
2017-07-19 12:00:00 000 issue 033089669 1498
2017-07-19 12:00:00 000 issue 033062620 3251

Thanks for any help you're able to give,

Chris Brown