Look at the last item in the InDesign preferences and tick Publish Online (Preview).
Seems like InDesign is not able to fetch the list of your published document from server.
Can you please re-try after relaunching the app. It should work then.
Can you please let me know your InDesign version, if you are on 11.2, please update InDesign to latest version 11.3.
Or you can try Help->Sign Out then Sign in and restart InDesign, it should bring back Publish button.
I've got a problem like this
updated existing document > publish onlie > bug displaying but not the thumbnails.
Important, I need to keep url link because customers had this link
Have you got a solution ?
If I am not wrong, Are you trying to re-publish and on republishing the thumbnails are not showing up?
Can you please tell me more what is showing up for you instead of Thumbnails?
I republished many times (only thumbnails displayed pages)
After several attempts, I decided to delete indesign preferences (hard delete, files inside folders).
Then I republished and it was ok.