It says please check credentials can't login and asking to login again.? Nothing has changed my end worked fine this morning.
just checked with ekm and they have said they did an update earlier and some customers are having problems. So if you have an ekm shop and you use the API and it's not working. Please ring them, the more people ring the quicker it will get fixed.
We have allowed for this change in Packing Partner, please see here: http://aimcosoftware.co.uk/forum/viewtopic.php?id=537