input and output of a 'user input task'

can you provide some more info about the issue and what are you trying to achieve.

Hi Meme02 ,

As far I know, The execution order will be 

1) Value in input

2) outputs

3) Save into in inputs

So first the value are saved in activity class parameters and then outputs are executed and in the save into fields are executed.

In your example, whatever the value in form is saved into ac!errMsg first, then output is executed i.e, null is saved into pv!errMsg and then again ac!errMsg is saved in pv!errMsg

Meme02 

For a user input task, the value you enter takes priority over any value set in the output.
Your test confirms this - the input sets "errMsg" and the attempt to clear it in the output is ignored.

 JayaPrakash Ravipati Ultimately, I expect 'errMsg' to be NULL. If I do not set SaveInto for INPUT, I can achieve this, so it is probably a mistake in my implementation, but I asked the question because I wanted to know the root cause and the relationship between INPUT and OUTPUT.

I thought the order was

1) Value in input
2) Save into in inputs
3) outputs

I need to leave the destination for saving inputs blank. Noted.

Thanks for support 
I need to leave the destination for saving inputs blank.

That is a very common configuration issue. Any output assignment that you configure will evaluate in a random order! Writing to the same process variable from INPUTS -> SaveInto and OUTPUTS calls for trouble.

The real answer to this is, of course, that conflicts like this should be avoided as much as possible (and luckily it's possible to avoid it at approaching 100% if design is done carefully), because one can never be sure what the order of precedence will actually be without either testing it or asking around (and i'm not completely convinced it is guaranteed to happen in a particular order either).