I solved it myself 5 minutes after I asked it here. I was so lame, because this was so easy. The projectors settings were messed up and when I resetted them I only needed to
- select Wi-Fi
- with laptop connect to it,
- with browser enter projector's IP
- download Acer eProjection management and install it.
And that's all. The only thing that something with settings were incorrect so just reset them to factory defaults if something aren't working.