expr = Cell[
   CellGroupData[{
     Cell[
      BoxData[RowBox[{"Range", "[", "10", "]"}]],
      "Input",
      CellChangeTimes -> {{3.738737785192193*^9,
         3.7387377884226933`*^9}},
      CellLabel -> "In[13]:="
      ],
     Cell[
      BoxData[
       RowBox[{"{",
         RowBox[{"1", ",", "2", ",", "3", ",", "4", ",", "5", ",",
           "6", ",", "7", ",", "8", ",", "9", ",", "10"}], "}"}]],
      "Output",
      CellChangeTimes -> {3.738737788836947*^9},
      CellLabel -> "Out[13]="

Rasterize[expr, "Image", Background -> None]

This shuts down Mathematica 11.3 on MacOS. If anyone knows of a work-around or a version where it worked that would be appreciated.

This: Rasterize[expr // StandardForm, "Image", Background -> None] does not crash.

@RolfMertig yes, but this is what I need it to look like:

I can also rasterize cell by cell with no background, for example, but I can't manage to rasterize a cell with a cell group such as the example above.

I would like to make something like the documentation. In the documentation, they have rasterized each input with no background. In this way, when they change the background in the HTML it looks like the cell is highlighted.

However, they didn't rasterize the whole thing like I'm trying to do. They only rasterized a cell at a time, which works. But it has other drawbacks.

 Rasterize[{expr}, "Image", Background -> White] (* Code that generates the image above *)

I have started 2 out of 3 Community Wiki answer to what I hope will be a canonical guide to the "Fresh Kernel" issue. This is the question.

I have started Prevention and New kernel for now. Still somebody have to start Cleaning and Initialisation/Dynamic.

I would really appreciate some help there.

If I do it, the cleaning part will be just some copy&paste from the links in the question.

@C.E. What're you trying to achieve with Background->None? Transparent background?

@C.E. ColorReplace[Rasterize[expr, "Image"], White, 0.1] would work...

It's not great but does work

@CarlLange You can see it in the documentation how, when a user hovers the input, the background color changes. This is done by changing the background color of the website, the image of the input is unchanged. It works because the input has no background. This is the effect I would like to have. (I have another way of getting achieving a "highlight" effect, but it isn't as good.)

The problem with ColorReplace, SetAlphaChannel etc. is with output like this:

If I were to use the ColorReplace method on this, it would also make the background of the plot transparent.

@C.E. That is really odd. On Linux too, the whole FE crashes.

@halirutan ok, thank you for testing!

@C.E. So you have an input/output cell combination. What things do you want to have transparent background for?

For example, if the cell expression corresponds to Plot[Sin[x], {x, 0, 2 Pi}, Background -> White] then I want the green part in the following to be transparent:

Cells can have Background set on them too...

@CarlLange Doesn't work for CE. Already tried to rasterize a cell with a None or Opacity[0] background.

:(