Hello,
The error message is quite clear on what's happening. This happens because you have more liquid boundaries with prescribed flowrates than the actual number of prescribed flowrates in the steering file.
In the steering file you must give flowrates in a list separated by semicolons, like this:
PRESCRIBED FLOWRATES = 0. ; 0.035 ; 0.070
But if you remove one of them, like this:
PRESCRIBED FLOWRATES = 0. ; 0.035
you will run into the same error. So what you have to do is to give more flowrates in the steering.
Regards,
Phelype