I was in this post looking for a solution, unfortunately did not find it, however I found what worked for me and hope it will also work for some other people.
I dont really know whos problem is it, the host, joomla or the extensions
my problem started so i decided to install the extension manually, then is when i figured i could not send files via ftp to my host, was getting a permission denied so I tought well then the host is the problem, however the hopst blames jommla´s extensions, anyway i dont care whos fault is it but the good thing is they had a solution in their control panel they have this toll named Fix File
Ownership and another Fix File permissions in the first one the explanation of the feature is
"This feature is useful when you have any files created by PHP (for example if you installed Joomla or used some file upload script), ownership of these files usually changes to "99" or "nobody" and you are not be able to delete or modify such files by FTP or File Manager, you will get "Permission denied" errors (such files can be deleted by PHP script only).
This tool fixes ownership for all files inside of your account, so you can edit or delete without problems."
note that they specifically mention joomla so i would say yes the problem is joomla, but there most be a problem with some extensions
anyway after clicking on those 2 fixes it took me less than a minute and was able again to install extensions
my web host is [url banned] i dont know if other hosts have this feature but you can check
You can view my free Joomla! extensions and templates at:http://www.tlacaelelrl.com/