The recent addition to GWE, 6M49 from Calvert to Wembley Aggregates, cannot be completed as it gets caught at a red signal outside of Twyford. On the map a 166 can be seen at the station itself, also at a red signal. I had to wait north of twenty minutes just for the signal not to clear, for either one of the trains. This cannot be a real life occurance. This is quite clearly a glitch and must be seen to at once.
As I’ve discussed in the technical forum, I had the same problem but you can do it. As soon as you start the service at Reading, put the reverser in, set to forward, release the brakes and set throttle to max (avoiding wheel spin) as quickly as possible and you should get far enough to get routed through Twyford before the 166 gets in the way. It’s not realistic but is a work around.