I was once using Mathematica 11 it all works fine - when I create new Notebook (.nb) input like 1+1 and press shift+enter, it shows output[1]:= 2 directly

But now for 12.1 when I create new notebook and do the same thing, it is treating my input 1+1 as plain text by default, when i press shift+enter there is just a linebreak.. no evaluation at all.

I find when I go to the menu -> cell -> cell properties and tick Evaluatable then the input can work well as Mathematica 11. BUT when i input Plot[x,{x,1,2}], it gives output -Graphics-!! Without showing what the graphic is! I then have to manually convert the output cell to StandardForm to show the graph! I have to do such things everytime, why is 12.1 getting me so much ados ..and how can i remove such tedious things making it funcation just like what mathematica 11 does?

Pardon me I'm a complete nooooooob and really searched goooogle tons of times not getting the answer....


1 Answer 1


These strange behaviors can be produced by:

  1. SetOptions[EvaluationNotebook[], FrontEnd`ReturnCreatesNewCell -> True] (or, in MMA 12+, just SetOptions[EvaluationNotebook[], ReturnCreatesNewCell -> True]since ReturnCreatesNewCell is now defined in the System` namespace).
  2. SetOptions[$Output, FormatType -> OutputForm] or SetOptions[EvaluationNotebook[], CommonDefaultFormatTypes->{"Output"->StandardForm}]

It's quite strange for a new Wolfram Mathematica installation to be like this. I'm not sure which situation you are in and whether there are other problems.

If you haven't made any major changes from a new installation, then I think the problem is likely due to the stylesheet. Try to set the stylesheet of the notebook to Default.

  • $\begingroup$ Its true the stylesheet everything going back2 normal when set to default... .thx $\endgroup$
    – gudako
    Commented Nov 22, 2020 at 4:04
  • $\begingroup$ I am confused about your statement about SetOptions[EvaluationNotebook[], CommonDefaultFormatTypes->{"Output"->StandardForm}], it has two meanings. Do you mean that (a) the CommonDefaultFormatTypes defines no other options except "Output", or (b) That the CommonDefaultFormatTypes option list contains "Output"->StandardForm among other rules? (b) is the default in MMA 12.x and 13. Also, IMO, it would be a bit clearer if you could provided non-destructive queries the OP could perform, e.g. Options[EvaluationNotebook[], ReturnCreatesNewCell] for the item 1, etc. $\endgroup$ Commented Jun 1, 2022 at 12:46
  • $\begingroup$ @kkm My aim is to make minimal change to the system, so I've used the nested syntax of queries. $\endgroup$
    – asd1dsa
    Commented Jun 3, 2022 at 12:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.