Logical Operators - Compass doesn't allow to change field

MongoDB University M001: MongoDB Basics
#1

When I try do clone the Once Upon a Time in the West document and set the field metacritic to null, compass just answer “not master”.

How can I fix this to follow the lecture?

#2

Hi @Fabio_83782,

Please share the Compass connection parameters for the sandbox cluster.

Thanks,
Sonali