Option to insert special characters is grayed out

[emera]

2020-12-01_12-34.png

software: LibreOffice Impress on Ubuntu 20

When I open pptx slides in LibreOffice the Greek symbols are replaced with white-space.
I don’t have the option to insert special characters and I think this is somehow related but I haven’t been able to find a solution.
One thing I tried doing is installing a Greek language package: (libreoffice-l10n-el), which had no effect.

thank you for any response

(edit)
Weirdly when I created my own slide on windows power-point and opened it in LibreOffice the symbols where preserved. I could insert symbols but there where no options for Greek characters (is there a specific package needed for this?).
But with the supplied slide there are no visible symbols.

slide with broken symbols
test_powerpoint.pptx

[gabix]

You can only use the command to insert a special character in a text box. So, are you sure that the object is a text box? Show a sample file, not that totally useless screenshot.

[LeroyG]

Hello @emera, Almost certainly is an issue with the .pptx format.

If you can type normal text, you should be able insert special characters. I can insert special characters in text boxes, shapes, and fontwork. LibreOffice 6.4.7.2 (x86); OS: Windows 6.1.

Click edit below your question to add more information and use the paper clip to upload a sample file.

[LeroyG]

@emera, I can add greek symbols to your sample document.

Most probably you don’t have the font Symbol installed on your Linux system; maybe that’s why the white-spaces.

The Symbol font name in the Format toolbar shows italicized when the cursor is at the right of a greek symbol?

If you choose menu Insert - Special Character…, you can select a Subset. Symbol font has no subsets like Times New Roman (both fonts in your document).

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Lest probably: When you open the document, do you see a warning like this one?

If you closed it without pressing the button, choose menu Edit - Edit Mode.

[gabix]

The problem is about the Symbol font. As LeroyG points, that font is, most probably, absent in your system. As far as I know, Symbol can be installed on many distros with the Microsoft core fonts package, but I am not sure. Anyway, this is a possible but quite a bad solution as Symbol uses some non-standard encoding. A better solution would be to use a TrueType/OpenType Unicode-based font. It might be Times New Roman, or Liberation Serif, or OpenSymbol. In fact, virtually any good modern font includes at least basic Greek letters, just play with the fonts installed in your system.

P. S. A Greek language pack is not necessary for this task, so, you can remove it (unless, of course, you are going to prepare documents in the Greek language).