Question

I have a pretty simple WPF application that is used to format inputs into a common format. It consists of little more than a bunch of textboxes and a few buttons. On almost all the systems that are running the application, they have no problems. But over time, a couple of them have encountered something odd.

On one machine, all text is gone. There are no labels, nothing shows up when they type, the tabs and buttons have no text (and are all minimum width, as if they had no content at all.) No amount of uninstalling/reinstalling or anything else has seemed to fix this system.

On the other system that has had trouble, every single character shows up as a little square. An uninstall/reinstall seems to fix this issue.

Any ideas on what may be causing this? As I said, I’m not doing anything fancy at all with this program. I’m not tweaking the rendering or even the templates for the controls. It is all WPF 101 simple.

Answer 1

It was indeed a font cache corruption of some sort. It was a little tricky to work out since the font cache likes to hide. Solution was as follows:

1. Start>Run>services.msc. Stop the service Windows Presentation Foundation Font Cache 3.0.0.0.

2. MANUALLY go to C:\Documents and Settings\LocalService\Local Settings\Application Data in Windows XP or C:\Windows\ServiceProfiles\LocalService\AppData\Local in Windows 7 or Later (this folder does not show up in explorer even with hidden items shows, so it must be done manually.)

3. Delete FontCache3.0.0.0 and restart the service. Restarted the WPF application and it worked perfectly.