1: You can try going into the preferences and 'Reset Workspaces'. Or follow the instructions in this link:
2: Do you possibly run some older plugins with Photoshop that may be causing a conflict?
Hi, thanks for the reply.
No I didn't run any plugins or instal anything etc. I used Photoshop yesterday and everything was fine. Today I open it and different story.
You may find an answer going through the threads with the same problem? Seems a few things can cause this.
Try reinstalling the software, it might solve this issue!