Is broken. It triggers a stop out of nowhere and just keeps the brakes on. (Waited 5 mins and no release on the HST but the 158 did release after a while). Both 158 and hst sets are affected. Edit. Turns out it's a Emergency brake application that won't release. Which means the AWS tripping is a instant scenario fail
I have the same problem. It always occurs in the same place, sometimes more than one place, in any given scenario. But in different scenarios, it will occur in different places. In some scenarios, it does not happen at all! If it is going to happen, it seems to happen not long after you have cleared an AWS warning for a signal. The warning light comes on in the HUD, but there is no warning bell. It is not possible to cancel the signal, and the train comes to a stop. To clear the setting, you have to shut down the power, set the direction to off and switch off the master key. Then you can switch it back on again, and set the direction.After the penalty period, the brakes will start to release and you can resume your journey.
You're probably hitting a set of TPWS overspeed grids. A known problem on MML is that the TPWS (and other aspects of signalling) are not set up correctly. This is apparently being remedied, but it'll take time. Meanwhile, as a workaround, after switching AWS on you can put TPWS into "temporary isolation" mode. There's a switch for it in the upper secondman's side of the cab. The TPWS panel in the driver's side of the cab should light up yellow to confirm this. AWS will still work as normal.
Its TPWS which doesn't only protect signals, it can protect speed reductions and other dangers too, so tripping on a green aspect is normal behaviour. I don't know how it is implemented in game but I found that reducing my speed more quickly when approaching signals and speed reductions near the three cities corrected the 'issue' for me.
It trips near Mountsorrel towards Leicester and that's not at a major speed reduction on Green signals. It's tripped on a green signal with me under the upcoming signal. I've also been speeding through (albeit only 2mph more) and it didn't. As far as I'm aware, skyhook know it's a problem.