Kacper

OK guys, huge thanks to "itimpi", you gave me a tip how to do this and I have figured it out !!!
 
Your key answer was here:
"Did you also do a repair (I.e. run without the -n option).   This is required to actually fix the file system on the emulated drive."
 
So my attempt to do check while array is started in normal mode did nothing. It just said 0 errors.
To conclude, in situation when one drive fails, then it says "context emulated" disk is marked with red cross but actually content of the disk is not emulated (you cannot see browse button next to Disk 1 name - see my first post). In this case unraid says "unmountable: blabla". In my case filesystem was corrupted on Drive 1.
So what You need to do is:
1. Stop array.
2. Star array in maintenance mode.
3. Click on removed or faulty disk and then run check for this one disk, however !!! MOST IMPORTANT !!! by default it adds -n option to check. It makes only do readonly check without fixing by default. Remove "-n" and click to check drive.
4. Stop array.
5. Start array in normal mode. Now you should be able to see emulated data from emulated drive.
 

 
See the screen shoot of my array before and after check.
Solution is so silly and it was impossible for me to figure it out from unraid docs. Doc are quite counterintuitive for me.
Community is what makes this product really cool and my faith in unraid parity has been restored. Thanks again Mr "itimpi", I get You a beer if You come to my city Wrocław in Poland!