With the release of Chrome v45 they have permanently disabled NPAPI support. This means that Practice Optimizer, dental.sikkasoft.com (which is Silverlight Based), does not work in Chrome anymore...until now. Here is one work-around solution that doesn't require you to use Firefox Internet Browser...
1. Download IE Tab from the Chrome Web Store. This extension allows you to run Internet Explorer inside a Chrome tab.
2. Once the extension is installed navigate to the the Options page.
3. Scroll down to the "Auto URLs" section and click "Learn more..." under "Action Recommended IE Tab cannot...". This will allow you to open secure websites in IE Tab.
4. Then click on "Click here to allow IE Tab to access...".
5. Click "Allow" on the popup window.
6. Click "Okay".
7. Go back to the Options.
8. Add "https://dental.sikkasoft.com/
*" to the field under "Auto URLs" and click "Add".
9. Close the settings tab.
10. Navigate to "dental.sikkasoft.com" in the Chrome address bar. You will see a second address bar open below. This is normal. You can now access Silverlight based products using Google Chrome.