Disabled Green Execution button

[Chela]

I am connected and have logged off and back on but the green arrow remains disabled. I have been working in PL/SQL dev for a while now and this is the first time this has happened.
I had to open up another instance in order to do my work but the first instance remains disabled. Why? What do I do to activate the green execute arrow?

Thanks.

 

[Marco Kalter]

Maybe the window you are trying to execute has been disconnected? If so, press the * button to the left of the connection on the status line of the window.

 

[Chela]

trying to paste an image but could not...

 

[Chela]

Thank you for the reply.