Flash must be installed and enabled on your browser

Is Flash installed? Probably not, if you saw "Adobe Flash must be enabled Click here for help" in a biocyc popup and selected the link to arrive here. However, as an independent check navigate to: http://get.adobe.com/flashplayer/about/. The page should have an initial animation at the top of a red bouncing cube with the Adobe Flash logo on it. If you don't see this, you absolutely need to install and/or enable flash.

Chrome

Chrome supports flash natively, so there's nothing to install. However, you have to have the browser configured properly.

Firefox

Flash is a Plug-In for Firefox. You'll need to install and enable it according to the instruction for you platform. Once installed, go to the Add-ons Manager, and ensure that Shockwave Flash is one of the Plug-Ins and that it is in "Always Activate" mode (that is, its enabled). Firefox, at this point, only enable you to turn Flash on or off; that is, Firefox doesn't have the granularity of control over Flash usage provided by Chrome at this point.