First things first. .ax files are used by various video playback programs to process video data streams; provides decoding and encoding capabilities, file parsing, audio and video de-multiplexing, video decompression, and rendering of video files; may also be used in the video recording and editing process.
Most likely installing a competing program has taken precedence over the one used by Ultra and Adobe.
There are two things I would try. The first is to reinstall Ultra and when asked if I wanted to install or repair choose to repair. You may also go to 'Control Panel' and choose the 'Programs and Features' and try repairing Ultra from there. If this is not effective you may need to reinstall Ultra from scratch.
Hope this helps a little,

Michael