There is no fix for Forum Runner - it's orphaned software at this point.
As previously explained to others...
The Boneyard has a mobile mode which is far better and requires no app.
Use your cell phone's browser, be it Chrome or Safari or whatever Windows Phone uses as a browser.
Go to your account from the phone browser or your desktop/laptop. Hover or click over your name in the upper right corner of the menu bar, next to "Inbox" and "Alerts".
A drop down menu will appear....let your eyes wander down the list to "Preferences". (It may be hard to see because on a phone, it tends to be a translucent field that lets the background show through. Squint really hard and you'll see it part-way down on the left side of the menu.)
Click on Preferences.
You will then be presented with a box announcing your "browsing preferences".
In the very top field, select "Mobile Style". It will be a little hard to see because it's often black writing on a dark blue background, but squint really hard and make sure Mobile Style is selected.
Scroll down, hit Save Changes and you are done. It will show you the mobile version of the site whenever you visit.
You can actually set up the mobile style from your computer and it will remember your preference when you log in with your cell browser.