IDL Problem Code 89 with alias illegal-dictionary-op 
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Execution Error
This is a fatal error that prevents IDL from compiling or running code
This problem, using types, identifies when you are using dictionaries in a way that is not allowed.
For example, when you try to add a dictionary and a list together:
idl
a = dictionary() + list()
;   ^^^^^^^^^^^^^^^^^^^^^ illegal dictionary opTo fix, correct your statement or re-write your code:
idl
a = dictionary('my-list', list())
;   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ OK!