Hammer is Glitching

When i Alt+tab our or click off of hammer and go back into it, all it does is drag around instead of creating stuff and it keeps happening can anyone help me?

What? Pictures or Video? Something to show us. Maybe explain a bit more so I can see your exact problem.

Either you have the camera tool selected, or that highly annoying bug. Try restarting hammer, restarting steam and restarting your pc.

I restarted steam twice its fixed now

1:When it happens,press the escape key
3:Finish map