There are any number of reasons why Flash might not be working on any given computer. Here are some possible causes and solutions:

The Flash plugin software is not installed, or the version installed is too old.

If your website was designed for the Flash 7 player, and your visitor has the Flash 6 player installed, they may not be able to see the Flash content at all, even though they do have the plugin installed. The first thing to check is that you have the latest version of the Flash player. (Download Latest Flash)

You need to empty your cache.

If you have been able to see Flash websites (or your site is not Flash), but cannot see the most recent changes we’ve made to your site, you may just need to empty the cache on your computer. Computers often store a certain amount of information about a website you have visited in the past. You may need to empty your cache before being able to see the changes to your website. Various web browsers have various ways of emptying the cache. Here are instructions for a couple common browsers:

Safari (Mac)

1. Click on Safari → Empty Cache.
2. Or, use this keyboard shortcut: Option + command + e

Firefox (Mac and Windows)

1. For Mac users, click on Firefox &rarr Preferences. For Windows users, click on Tools → Options.
2. Click on Privacy.
3. Next to Cache, click on Clear.

Internet Explorer (Windows)

1. Click on Tools &rarr Internet Options.
2. Under Temporary Internet Files, click Delete Files.
3. Click OK.
4. Click OK again.

Visitor is behind a corporate firewall.

This can often happen while trying to browse a website with Flash in an office environment. Make sure the IT person hasn’t set up the network to prevent Flash content from working.

Visitor has software on their computer preventing Flash from showing.

Often Internet security software or spam protection software also prevents common plugins from working. Presumably this is to block advertisements which are often built in Flash. Such options can be changed within this software.

Visitor is using AOL’s browser, and can’t see some of the images.

AOL uses proprietary, nonstandard methods to recompress the already-compressed JPEG pictures on your site. Without a bit of extra effort, this can confuse Flash, and your graphics might not show up at all under some circumstances. One solution is to suggest that visitors to your site not use the AOL browser, but instead a better (and free) browser such as Firefox.