Bus line 2, which serves the St. Catherine Cathedral, is temporarily out of service, for an unspecified time.
Starting from Saturday, the 4th of February, line 22 can be used to come from Utrecht central station (Jaarbeurs side) to the museum quarter. You can get out at the stop at Korte Smeestraat to easily reach the St. Catherine’s Cathedral. This stop is just a few meters from the former bus stop Catherijneconvent.
More info in the OV Utrecht website (in dutch): https://u-ov.info/contact/actueel/tijdelijke-pendeldienst-ivm-omleiding-lijn-21/