- Internal error: Unknown data type allocated to parameter &

What causes this issue?

The function module assigned to the function call you selected contains
parameter &V1&. Due to an internal error, the system was unable to
assign any of the data types used in the function call to the data type
of this parameter. For this reason, the parameter cannot be processed
correctly in the function call.

System Response

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

How to fix this error?

INCLUDE NA_SYSVERW OBJECT DOKU ID TX LANGUAGE EN

Error message extract from SAP system. Copyright SAP SE.