Pos0Aut and Pos1Aut are set to "1" but there is no error message in runtime. Is that normal?

I expected an error in this case.

Hello Ashadako, 

This condition is a part of the error handling methodologies adapted in Advanced process library. Have you checked the faceplate of this block? I presume you should be getting an 'invalid signal' error on the faceplate under such a situation where both Pos0Aut and Pos1Aut are 1 and the valve is in Auto. (refer attached screenshot).

Just to add the context of this 'Invalid input signal' error, this error is output if inconsistencies are detected between associated I/Os. The close and open commands cannot be output simultaneously to the valve, for example.If the block algorithm detects an invalid combination of input signals, an error number (ErrorNum) is output that depends on the block type. In the case of motors, valves and batches, the faceplates’ standard view will additionally output the text “invalid signal”.

Hope this helps 

Error handling is explained as a separate topic in the APL Library Manual (Section 2.1.6) if you are interested to know more.