We’ve become aware of a recent Microsoft Windows update that may cause issues with web servers running on Windows machines.
Since there is a problem with specific Microsoft updates, we recommend checking your Patient Booking Gateway is still accessible each time you install Windows Updates on your server computer.
If you are affected by this issue, your Patient Booking Gateway may not load and will instead return an error such as “ERR_HTTP2_PROTOCOL_ERROR”.
The affected updates are:
KB5066835 – October cumulative Windows 11 update
KB5066131 – October .NET Framework update
If either of these are installed, and your Front Desk - Patient Booking Gateway is inacessible, the steps below should restore normal operation until Microsoft releases a corrected version.
The steps provided below are outside our normal support scope and are offered in good faith based on current information. Proceed at your own risk. If you’re not comfortable performing these actions, or if your system is managed under a corporate IT policy, we recommend consulting a qualified IT professional before making any changes.
Resolution
1. Check whether the updates are installed
Press Start, type View update history, and open it.
Scroll down to Uninstall updates.
Look for either KB5066835 or KB5066131 in the list.
2. Uninstall the update
Select the update (start with KB5066835) and click Uninstall.
Follow the prompts and restart your computer when asked.
If both are listed, remove KB5066835 first, reboot, then repeat for KB5066131.
3. Pause Windows Updates temporarily
Go to Settings → Windows Update.
Click Pause updates and choose at least 7–35 days.
(This prevents the same update from reinstalling automatically.)
4. Test
After the restart:
Try accessing your Patient Booking Gateway again via your business website.
The site should now load normally.
Once Microsoft releases a fixed update (hopefully within the next cumulative release), you should be safe to resume their automatic updates.