I copied recursive all directoriesI had to reinstall the extensions, they were still listed under Extensions, but not working and the icons were gone
I am glad that you have solved you problem! For understanding:(1) So, for testing purpose you simply copied ALL the content of the old profile's directory to the new profile's directory. (2) And after this test showed promising results then you once more created a new profile, but this time have only copied the files of interest to it, the ones which are explicitly emphasized on the support page: https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile Finally, as announced on the support page, the extensions still needed to become reinstalled.
Did I understand it correctly?