I am running firefox v 15 on my mac pro & I can not upgrade it to 16.0.1
It says some items had to be skipped.
all must be unlocked and not be in read only or no access
I unlock all and it still won't install
If there is an issue with update or permissions the better, quickest and safest way is to download and install firefox:
1. Download a copy of the latest firefox from http://www.mozilla.org/en-US/firefox/all.html
2. Trash the current Firefox application to do a clean install.
3. Install the version that you have downloaded.
Do not select to remove your personal data, your profile data is stored elsewhere in the Firefox Profile Folder, so you won't lose your bookmarks or other personal data.
see also: Installing Firefox on Mac
Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.