Hi! I see that your PDF Reader Pro won’t open after the update. Let me help you get it working again. Just to clarify first: when you say it "won't open," do you mean the application itself won’t launch at all, or is the app opening but PDF files inside it are not loading? Also, have you tried restarting your computer since the update?

Meanwhile, here is a basic set of steps we can try:

1. Restart Your Computer: Sometimes updates need a restart to complete properly. If you haven't done this yet, please do so.

2. Run as Administrator: Right-click the PDF Reader Pro icon and select "Run as administrator." This can help if there are permission issues blocking the app from launching.

3. Compatibility Mode: Since you are on Windows 10, right-click the app icon, go to Properties > Compatibility tab, and check "Run this program in compatibility mode for" and try Windows 8 or 7.

4. Reinstall the App: If the above doesn’t help, uninstall PDF Reader Pro completely from your system, then download and install the latest version fresh from the official PDF Reader Pro website. Sometimes updates can get corrupted.

5. Check for Conflicting Software: If you have other PDF readers like Adobe Acrobat installed, they might interfere. Try temporarily disabling or uninstalling other PDF tools to see if that helps.

6. Check for Windows Updates: Ensure your Windows 10 is fully updated. Occasionally, OS updates and app updates need to align.

If you have already tried any of these or “Run as admin” and compatibility mode don’t do the trick, please let me know which steps you’ve done, and if you see any error messages when trying to open PDF Reader Pro. I’m here to help you get this fixed as smoothly as possible.