Access Denied and Libraries Not Recognised

Hi, I have two stumbling blocks at present... 1. After having had a system crash, I tried to manually restore the system from a back-up by extracting the Files System back-up zip file in the original root directory (sql database backed-up separately due to shared hosting, php or other drupal environment settings that caused an Internal Server Error when using backup and migrate module to back-up entire site). This seemed to work fine, but although I am user1 administrator and can access all other administration menus, I am denied access to the 'Manage Display Settings' menu. I have no idea why or how to fix it. 2. Status report indicated that it could not find ffmpeg or video.js. I have installed ffmpeg in the sites/all/ folder as directed but, it will not recognise it. I have searched for packaged versions in case the problem is like that with pdf library which, required the 'dist' zip file rather than the src version, but to no avail. I have also switched the ffmpeg name to FFmpeg as it is often written in documentation. Nothing seems to work. 3. Also, the built in CDN service does not seem to work for video.js in Opigno. To confuse matters more, the info in the status reports and often web documentation refers to it by the file name video-js. Eventually found video.js library in the correct pacagek format: . I downloaded latest stable version 6.7.3. and then got the following message in status reports... "The installed version of the Video.js library is not supported. This version of the Video.js module only supports Video.js version 4. Download Video.js version 4 and extract it into the sites/all/libraries/video.js directory or download Video.js module version 7.x-2.x to use Video.js 3." Version 4 is so antiquated I almost could not find that either! Are there any plans to bring this a little more up-to-date? Can anyone point me in the right direction to get a packaged version of ffmpeg or otherwise advise me how to solve these two niggling little issues that remain outstanding? I.e. the Access denied problem and ffmpeg. Btw, Should I install the drupal CDN contrib module, to make the CDN work or will that interfere with the pre-installed profile somehow?? Can anyone advise me please? Kr, Chris