After upgrade to BW 7.4 - replacement variable message: Could not be processed

Hallo,

in some queries we have some replacement variables. These variables read attributes from an infoobject,

We upgraded our BW-System to 7.4 and now after entering the variable values in the variable screen of these queries, the message "variables for characteristic XYZ could not be processed".
Ignoring the message and clicking on the button "OK" of the variable screen again, the query opens without any Problems.

We don't know why the replacement variables could not be processed...

Is there a way to get the queries working immedialtely?

Thanks and best regards!

Christian