Message type: E = Error
Message class: BRAIN_SUP - BRAIN messages (for use by support)
Message number: 018
Message text: Variable &1[&2] cannot be replaced from &3[&4]
Variable &V1&[&V2&] should be replaced with the value of variable &V3&[
&V4&]. But &V4& is not input enabled.
The system does not support this replacement.
Variable &V2& cannot be used.
Check the variables &V2& and &V4&.
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.