I have been having the same problem, and no amount of uninstall/reinstall fixed it.
However, I figured out a workaround : )
I created a folder, "ffmpeg23" in C:\Program Files (x86)\NCH Software\Components
I opened took "ffmpeg23.exe" in 7-Zip.
Inside was one file, "avcodec-55.nch.dll". I extracted it the ffmpeg23 folder created above.
Then, I copied that folder (ffmpeg23), and its contents, to "%AppData%\Roaming\NCH Software\Components
This folder gets created "next to" ffmpeg22.
I started VideoPad and I was able to import my file.
Your mileage may vary but I'm betting this workaround will work for others.
Steve