Manual Raw Reflection, adding a sort produces an error

Any ideas on the below error?
This is produced as it rebuilds the reflection after clicking on SORT for the id column (an auto increment field in MySQL)
Without the sort, it is able to build the reflection.

DATA_WRITE ERROR: Failure while attempting to spill sort data to disk.

Location 0:0:7
Fragment 0:0

[Error Id: 9db68bd0-e86e-4ba3-b6e7-7ef3f0f22f73 on ip-XXXXXX.ec2.internal:31010]

(java.lang.NullPointerException) Container schema is not set. Either schema was not built, or schema was cleared.