Cannot write to read-only data
One of the following has occurred:
- You’ve attempted to initialize a field in a class that was declared with the READONLY modifier. The value of a READONLY field can only be set during declaration or in the constructor of the class.
- You’ve attempted to assign a value to a parameter defined with an IN modifier.
- You've attempted to write to a READONLY structure or use READONLY method returns in a writable situation.