Signal failure near York causes significant train delays affecting services to Darlington. Disruption expected until 1:30 PM.

Basically, there’s no signal between York and Northallerton. Trains can’t go north from York, and trains also can’t go south from Darlington. Several routes have problems because of this.
CrossCountry is affected, impacting trains between Edinburgh and Penzance, as well as Aberdeen. Grand Central trains between London and Sunderland are also affected. LNER trains have delays too, impacting services between London and York, Edinburgh, and other places.
Lumo trains from London to Edinburgh also face delays. Northern trains are messed up, affecting services between Sheffield, Leeds and Blackpool to York. TransPennine Express trains have delays too, with the Liverpool to Newcastle routes impacted.
You can still travel between Darlington and York. Three replacement buses are available to help people get where they need to go.