User Parameter not set! &

What causes this issue?

User Parameter not set! <(>&<)>

How to fix this error?

Goto System -> User Profile -> Own Data -> Parameters. Enter a new
Parameter Id = 'ADS2K_REPORT'. Parameter Value = ' PDF' for PDF output
or 'SF' for Smartform output. Enter the desired value in User
Maintenance and click on Save. Execute again to get the output. For more
information on enabling PDF forms output, please refer to Note 834573.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.