Wolfram Mathematica does not evaluate at all

Hi, the title tells everything, I do not know why it doesn’t evaluate a thing. Even if I write down 5+6 and press shift+ctrl as usually it does nothing it just moves to next line and that’s all. I installed it a month ago and used it once and it worked very well as I remember. I deleted it and installed again previously but of course it had no effect at all. Do you have any suggestions?
Thank you.

Other informations: Wolfram Mathematica version 12.0
OS: Windows 10

Try shift+enter instead

Oh, I typed that wrong. I did meant enter instead of ctrl.

Hi Terezija,

Have you tried holding Shift+Ctrl during the start-up in order to reset your frontend preferences, assuming that they may have gotten mangled up?

Compare:

Otherwise please reach out to Wolfram Technical Support via

and include your activation key, if you can, as well as any comments on how you may have customized or modified your Mathematica or Windows 10 recently.

Thank you,

Peter Fleck

Manager, Wolfram Technology Group

Obviously you have 12, so you can look in your kernel menu and see if the kernel is running - and also choose “Evaluate” from the menu (not just keys)

It is possible for you to have gone into kernel settings and hacked so that your kernel won’t start or won’t connect to the notebook on your desktop (i don’t suggest changing the settings unless you know what your doing)

I doubt either occurred - this doesn’t sound like a real problem report “yet”

Hi, I resolved the problem and now it works normally.
Thank you for your help.