What fonts? What format? What version of Windows? What version of InDesign?
Have you tried putting them in the InDesign fonts folder?
If you put a font in the Font folder located at Program Files/Adobe/InDesign [version]/Fonts folder, InDesign can almost always see it.
Also, once I too had the same problem and the below information from this thread Fonts not appearing in InDesign helped me: (I am only adding the information that helped me and not the entire thread comments)
"If InDesign does not see the fonts added to the Fonts folder, either ID doesn't like the way they are made (ID is very fussy about fonts), or they have some problem, as with Arial Narrow on Windows (been discussed to death).
You can also try scrolling through the list and look under the family as well as the foundry name. Also, Cyrillic and Asian fonts are in sections by themselves at the end of the list, and after those are fonts that ID is unable to classify, so take a look at the bottom, too."
Do check the thread above for more information!
Still if this doesnt help check this troubleshooting page especially Solution 6: Fonts don't appear in the Font menu | Adobe InDesign 2.x, CS, CS2
Do let us know if you are able to resolve the problem at your end
The fonts are Alex Brush and Cabin. They are OpenType font files. I'm working from Windows 10 and InDesign CC 2017.
I've tried all the suggestions from both those pages, but it still doesn't work.
i downloaded the fonts from Free Fonts! Legit Free & Quality » Font Squirrel and I am able to see them
Since none of the above mentioned methods worked for you, you can try downloading the fonts from the link i posted?
What font version?can be seen here...
I tried downloading the fonts from your link but they still would not work in my file. However I tried creating a new InDesign document and I was able to use both those fonts without any issue. So it seems to be working with InDesign, just not with the document I have already created. Do you have any idea how I can fix this so I can keep my current document, as it already has a lot of content?
Save the document that's causing the problem as an IDML file (File > Save As > InDesign CS4 or later [IDML]). Then reopen the file. The file could be corrupted and this should fix corruption.
This worked! Thank you all for the help!