I’m having a similar problem. (“permission denied … Cannot update file …Installation failed.”)
But my problem is worsened by the fact that I’m a newbie to WordPress and am clueless when it comes to code or editing. (I’ve recently converted from the now-defunct iWeb, where my ignorance was bliss.)
Reading several forums, I understand that I need to change some code somewhere, but I’m not too embarrassed to say that I don’t know how to do that.
Even reading WordPress’ own troubleshooting page, it appears to sound simple … Yet, here I am.
Is there no “newbie-approved” solution for fixing this error? (Is learning to code the only way to solve problems in WordPress?)