Ultraviolet light can be harmful if you look at it or bring it close to your skin. For these reasons, we have designed safety features into our SteriShoe® sanitizers to prevent the lamp from lighting when it is not enclosed in a shoe. Please refer to the Instruction Manual for your specified model for troubleshooting tips on how to overcome the safety features. You may also click here for more information.” *I would like the link to take them to the “Instruction Manuals” tab. But I would like the tab updated to “Instruction Manuals/Troubleshooting” to be more clear. The manuals do contain troubleshooting steps.