From the FGW website :

Train services between Reading and Basingstoke are being disrupted due to a earlier broken rail in the southcote Junction area.Engineers have worked as fast as possible to restore services to normal. Short notice cancellations can be expected.

The 07 minutes past the hour services from Reading to Basingstoke will operate. The 37 minutes past the hour from Basingstoke to Reading will operate. The 39 minutes past the hour service from Reading to Basingstoke and the 08 minutes past the hour from Basingstoke to Reading are cancelled.