Expression.Error: We cannot convert the value null to type Logical.

[Lucy1234]

when I merged a query and expand the table, I met the error as below. 

Expression.Error: We cannot convert the value null to type Logical.
Details:
Value=
Type=[Type]

but I checked all my data there is no logical datatype. I also merged the same query with different Key it can work. how to solve this?

[bhelou]

can you share some sample ? 

[Lucy1234]

my code is as above, I merged same table here, but the secode time I met the error.