Wow, that sounds awful...
So maybe it's not even related to other modules, but some... cache problem somewhere? Be it browser or server-side? A Heisenbug.
It remains a complete mystery. I started enabling other modules on my clean install and boom - off it went again. Of course, removing those modules didn’t make any difference so I couldn’t...
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Can you post more details about the error you are getting? And perhaps a screenshot?
See attached
Please see this:
https://forum.backdropcms.org/forum/cant-install-modules-error-installin...
It has to do with your folder's permissions.