Expression evaluation error [evaluation ID = Y38GMQ7D] at function a!recordList: Cannot execute a query with a blank field name. (APNX-1-4198-000)

Question

I have a CDT named "LNE_Servicing" which has 2 foreign keys, one from CDT userList and one from CDT soldAppliance. 
 
 When I try to create a recordType for Servicing and check the record it gives me the error:

The Requested Record Type Is Not Available Expression evaluation error [evaluation ID = Y38GMQ7D] at function a!recordList: Cannot execute a query with a blank field name. (APNX-1-4198-000) 
 
 In the performance tab of the record type it shows:

Could not calculate performance. Please check record type definition. 
 Expression evaluation error [evaluation ID = RUAXQRTA] at function a!recordList_ui_design: Cannot execute a query with a blank field name. (APNX-1-4198-000)

On clicking edit list in the List tab it shows: 
 Error Evaluating UI Expression

Expression evaluation error at function a!gridField [line 27]: Cannot execute a query with a blank field name. 
 
 This is my servicing table:

leeaan0001 · Accepted Answer

The problem got solved. Apparently the issue was that servicing table didn't have a primary key of it's own. I edited my CDT and now it works fine.