In connection with my efforts to figure out how to move wikis and workspaces, I tried the wiki and workspace export and import functions.
The export works no problem, and the resulting zip contains attachments and a main index.xml containing all the page content for the site
I then created a new wiki, and attempted to import these zip files. In each case the browser takes a few seconds to upload the zip, but then does nothing -- no confirmation that anything was uploaded, no error message, nothing. And no new pages appear.
So, something looks broken. One minor puzzle is that the index.xml page is encoded. That is to say, all instances of opening and closing angle brackets are encoded to ampersand-lt;...ampersand-gt; and so on. Conceivably your uploader decodes that, but it's at odds with
https://zohowikihelp.wiki.zoho.com/Import-Format.html which shows the upload format not encoded in this manner.
(For what it's worth, if import DID work, it looks like one should be able to move wikis and workspaces, and fix up links with some judicious search-and-replace, though that's made much more onerous by the entity encoding just mentioned. Not sure how permissions are dealt with though.)