Some firewall/anti-virus software can conflict with TuneUp causing the user interface to show an error message at launch:
TuneUp was unable to load.
ERROR syntax error all.js 1
ERROR Output is not defined
tuneup.html?language=en-US&player=itunes 251 (please note: this number may vary)
To resolve this issue, try adding the URL http://server.tuneupmedia.com/* to your safe list in any/all of the following programs: Windows Firewall, McAfee, Norton, Trend Micro, Kaspersky or any AVG product.
Additionally, some wireless routers also can have a built in firewall that can block TuneUp's user interface from loading. If TuneUp does not launch properly after adding the above URL to your safe list, please try disabling any built-in router firewalls.