Changing landing page gives error

When I try to change the landing page I get the following error:
“TypeError: Cannot read properties of undefined (reading ‘value’). See dev console (F12) and/or server logs for more info.”
Pressing F12 I don’t see any error codes. In the log file there is a bunch of this:
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration but could be safely merged (-3303.796s). This message will only show once per batch. (aw_transform.flood:48)
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration and could NOT be safely merged (-434.011s). This warning will only show once per batch. (aw_transform.flood:56)
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration but could be safely merged (-0.013s). This message will only show once per batch. (aw_transform.flood:48)
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration and could NOT be safely merged (-598.445s). This warning will only show once per batch. (aw_transform.flood:56)
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration but could be safely merged (-284.096s). This message will only show once per batch. (aw_transform.flood:48)
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration and could NOT be safely merged (-300.87s). This warning will only show once per batch. (aw_transform.flood:56)
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration but could be safely merged (-318.668s). This message will only show once per batch. (aw_transform.flood:48)
2021-12-08 16:39:06 [WARNING]: Gap was of negative duration and could NOT be safely merged (-318.668s). This warning will only show once per batch. (aw_transform.flood:56)