Sorry about the long title post, but I wanted to ensure the relevant factors were all included for clarity.
This post will be of interest to anyone who wishes to use the new Google Gears option within WordPress 2.6, or the flash-based uploader for image files etc., but is not able to.
The first thing to check is if your browser’s Flash plugin is up to date. Visit this page, and towards the top, where it states “You have version x,y,z,a installed”, make sure you have 9,0,124,0 or later listed. You may find earlier versions of the Flash plugin will work OK, but if you have a problem, it is best to discount all potential causes step-by-step.
If you are already up to date, or you have upgraded, and the problems remain, then the next thing to check is that you do not have a Flash applet blocker loaded within your browser. If you see a small ‘F’ symbol on pages where others see flash applets, you need to whitelist (allow) your own website for all flash – it is not enough to temporarily allow the flash applet on a case by case basis.
Problems still remain with Google Gears and/or the Flash File Uploader? In which case I’ll bet you a small bottle of vodka that you used the WordPress Automatic Update plugin to upgrade. You will most likely that find two SWF files are missing from your installation. I had this issue which was stopping Google Gears from working. One of the files involved was the media uploader one.
The easiest way to check if this is your problem is to FTP in to your site and look at /wp-includes/js/swfupload/ – if the file swfupload_f9.swf is missing, and also flv_player.swf from wp-includes\js\tinymce\plugins\media\img
is missing, then we have discovered the root of the problem. The solution? Download WordPress 2.6, from here. Extract the files to a temporary directory on your hard drive and manually upload those SWG files to your site in those locations I mentioned.
So this should sort your problems out for your current installation of WordPress. What to do about next time? If you enable your site within your flash blocker add-in before you next use the WPAU plugin, said files should be upgraded fine 🙂
Information collated from the WordPress support forums – you can see my post here.