Ok, last friendly game the same thing happened but I beleived that I've made mistake and didn't complain (although there were several other users also complaining). But now I'm sure what players I've set to play, on what positions, and checked after saving the line-up. In my game, some different lineup played which resulted in total disaster.
This is crucial thing to be working. If match lineup doesn't work, it destroys all my efforts to figure out how to play, and make improvement in game. Once again, there is no official guide how to create players. If I don't know how players develop, and can't test/play as I want to play, then what's the point of this game unless it is to waste time...
I know that this is still in development phase, but you have to do something about this issue.

unfortunately:
1/ no, i've checked
2/ no, i've checked
3/ no, none of sold players wasn't put to play

by looking on orders after i saved them and/or swithching and looking attack/defense/tactics tab before saving?

hrm...

well it seems to me that you can't check your lineup during a game after the game, so you are at least deceiving us on that point. Judging by when you posted, it couldn't have been a default setting b/c they didn't exist when you posted this...

But either way, I think it'd be easier for us to help you if you posted your lineup. I myself have found some illegal formations that are not listed as such when you are setting them. So anyway, post your lineup and we'll go from there.

Best wishes,

Squish

Perhaps you sold a player that was going to be in your line-up?

Who knows. As you said it works now, so that's all that matters!