Possible issue in New Message Center Archiving Workflow Adobe Campaign Classic
Starting build 8653, a new mode allows users to run one workflow per execution instance, you can refer to the switch document on the following link Switch to Message Center Archive Workflows
I have deployed a couple of ACC 7.0 18.6 sandboxes on my AWS environment and have found that with each one of them the new message center archiving workflow fails at the end of the the work, spefically the "End" activity, it also fails on new upgraded environments where this new archiving workflow has been made accessible.
06/02/2019 10:30:36 end SCR-160012 JavaScript: error while evaluating script 'mcSynch_local/end'.
06/02/2019 10:30:36 end JST-310000 Error while compiling script 'mcSynch_local/end' line 2: vars.dateCurrentStart.getTime is not a function.

Has anyone come across this issue as well, if so how did you fix it? I have spent some time fixing the OOTB workflow and introduced a bit of custom code to get around the problem.
Original code
setOption('MC_LastQuarantinesSynch_' + vars.cellId, new Date(vars.dateCurrentStart.getTime()));
var sg = new StringGroup("nms:messageCenter");
logInfo(sg.synchDone());
instance.vars.running = false;
My Custom Code
//start fix David Garcia
vars.dateCurrentStart = "";
var optionName = "MC_LastQuarantinesSynch_" + vars.cellId;
var option = getOption(optionName, false);
if( option ) {
vars.dateCurrentStart = option;
//debug logInfo("option "+option);
} else {
vars.dateCurrentStart = vars.NOW;
}
//end
setOption('MC_LastQuarantinesSynch_' + vars.cellId, new Date(vars.dateCurrentStart.getTime()));
var sg = new StringGroup("nms:messageCenter");
logInfo(sg.synchDone());
instance.vars.running = false;
The issue is that the vars.dateCurrentStart variable which needs defining.
Has anyone come across the same issue? is this something Adobe needs looking into? can you guys replicate it.