You are attempting to load up the map via tab, this is a route - not a scenario, to drive in it you'll have to make a scenario of it as I didn't make a QD scenario due to the fact this was a teaser.

When I try to start this simulation from the Drive/Workshop menu, under the "Required Add-ons" section, it shows the ECMLS Add-on is required. I already have the Add-on, and it does work, I am not given the option to "Drive", but "Purchase the required Add-on". I've unsubscribed and subscribed, rebooted train simulator, even restarted the computer. Any ideas? Very much appreciated.

@JPT1987 DPSimulation - as far as I'm aware - haven't done the Hertford loop, only the extension to Royston which is the branch off from Hitchin.

is DP simulation make the full hertford loop at last

If you read the description it states: Version 0.5 offers users with ECML South: London - Peterborough to go further beyond Bowes Park up to Palmers Green (It is only an extra mile longer BUT V1 will allow you to continue to Gordon Hill with scenery to follow (as realistically as possible seeing how I'm a beginner at scenery making)).

At this current moment due to coursework in my final month of this year in college I can't make time for V1 so it will have to come in July or August if need-be

How far through is this?

If you're referring to this workshop submission then no, this is a sneak peak of whats to come of the Hertford Loop (as stated in the description). Description has a schedule of when the updates are coming and what is included

is this the whole of the hertford loop

Thanks. I will try man. See this link at DPS ...

nice !! take as long as you need though i would rather see this completed and ready as opposed to rushed neverthless keep up the good work !