In LIMS-plus v5, we use a Java applet (jZebra) to poll your list of printers, including bar code printers, so these can be presented and accessed through the application. If that applet doesn't run when you first open the LIMS-plus v5x site, then your printers will not be listed.
Check and Update Java
1. Visit http://java.com/verify and make sure that Java is initializing.
2. While you’re there, make sure you have the latest version of Java installed. Make sure there are no other versions of Java also installed that might be interfering.
3. Open your Java control panel (in the Windows Start search, just type Java) , select the Security tab and set Security level to High, enable Java in browser, then click “Restore Security Prompts.”
Adjust Internet Security
If you still cannot see your printers, add the domain to the Intranet Zone in Internet Options and make sure that Compatibility View is disabled.
Clear the browser cache, close it entirely, and relaunch LIMS-plus.
If prompted, after clearing the cache, you want the browser setting to Check for new version of web page 'every time I visit a site.'
Full Java Re-install
If none of the above allows your printers to display, then unistall and reinstall Java.