First of all, sorry for the inconveniences!
This is an issue we are currently investigating. So far we know that there are interdependencies with the HCS extensions from the community contributions. If you have these extensions installed, could you try uninstalling them, as discussed here https://forum.knime.com/t/text-processing-extension-are-missing-after-upgrading-to-version-3-6/11521/6?
Please let me know whether it solves the problem for both extensions, textprocessing and palladian.
Thank you.