UE 5.1 is building project but there is blank grey view? This problem is only at my home desktop. Same project launches perfectly at my work desktop. Neither it doesn´t create completely new project - any kind. Where is the problem?
Try loading default layout for editor.
Greetings @SSuvereni
Welcome to the Unreal Engine Forums! I’ve actually had that issue before. As Nawrot mentioned, try opening the default layout for the editor. Also, if it’s a specific project doing this, try removing the ‘Config’ and ‘Saved’ folders from the project folder and load it up again. (Note: Don’t Delete them. You may want to put them back in afterward. I’d recommend just moving them to your desktop temporarily while you test) I hope this helps!
Yippee 
Thanks for golden advices - everything is perfect now
If that doesn’t work, just try press ALT+G.
What this does is restart the view of the project to “Prespective Mode”.
It was my solution because somehow, I changed unintentionally the prespective view to “Top View”.
If you see that some of the directional lines (X,Y,Z) are missing when you open/load the project and that grey screen appears, you have the same problem for sure and this will fix-it for sure.