There seems to be a problem with 5.2.6 and some earlier versions for converting text to path.
Version 5.1.5 does work and for Windows you can download the portable .zip:
https://download.kde.org/Attic/krita/5.1.5/krita-x64-5.1.5.zip
The Linux appimage is here:
https://download.kde.org/Attic/krita/5.1.5/krita-5.1.5-x86_64.appimage
The macOS .dmg file is here:
https://download.kde.org/Attic/krita/5.1.5/krita-5.1.5.dmg
The advantage of using the Windows .portable .zip or the Linux appimage is that you can use it independently of any other version you may have (but not at the same time).
After you’ve converted text to path using 5.1.5, you can then Save it and use 5.2.6 to carry on working with it.
I’ve informed the text tool developer here:
Text Tool Thread - #168 by AhabGreybeard
We must now wait patiently for it to be fixed.