I have been using Dropbox for years. I recently upgraded to OS X Big Sur. After the install, I had to change my user name from rshane2 to richimac. This step changed the name of my home folder as well. After this action, Dropbox will not reinstall. I have read the two other posts on this matter, but solutions presented in each do not solve my problem. I am attaching screenshots of the dialog box, error message and a text file presented to me in the error message. As you can see in that text file, Dropbox still thinks I have my old user name. I do not know what to do to fix this problem. I would be grateful for advice. Thank you. Rich
Let me doubt that you have followed exactly everything if the error message you have posted in OP is received after that. If you have tried it after that (i.e. posted log is a obsolete one), post the actual error log.
If you still can't achieve anything, post exactly what you typed in the terminal and the result, if any, exactly as appear there.
One more thing, hope you have stopped Dropbox application in advance and start it anew after that!