Greetings,
I came home tonight and went to launch the Proton VPN client and it will not start with WIn 10. I tried to unistall and reinstall then reboot and no good. Went to an earlier version as well and no luck. Did anything get released on Windows that is blocking the Program?
Solved:
I uinstalled two Microsoft windows KB updates that were dated for today. Rebooted, once the PC came back up and installed the updates (assuming they were the same ones) VPN is able to launch now.
Update to this:
So the two KB ( KB4515384 and KB4514359 ) that I had deleted keep coming back later to reininstall. I got in touch with Tech support and they gave me a few things to try. I was not aware that MSI afterburner and RivaTuner had issues with the program. With that in mind I tested it out. I reinstalled the two KB files and left MSI/RIva turned off and Proton launched just fine. Enabled MSI/Riva and tried launching Proton and it would not start. So strange that this all of a sudden start happening now and not back in July when I installed MSI/Riva when I upgraded my GPU.
So my work around right now is to leave the KB installed and if Proton gets closed, then to shut MSI/Riva down, start Proton, and then MSI/RIVA. Once Proton is up and running it has no problems with MSI/RIVA.
Heck I even put Proton on Riva’s Whitelist, but no luck there.
I came to this sub because of this issue. I will try to remove the updates.
I only create this account to say Thank You. 
I had a similar issue caused by RTSS and which caused “Malwarebytes Windows Firewall Control” (WFC) to crash.
The work-around is the following:
Rivatuner Statistics Server is causing this. Open it and set Application detection level to None. Otherwise, this software may try to determine the FPS for WFC which uses the GPU to render the user interface.
Heck I even put Proton on Riva’s Whitelist, but no luck there.
This actually works, at least for WFC. Add it to the list and then set “Application detection level” to “None” specifically for this executable.
I have tried uninstalling ProtonVPN, restarting the PC, and then installing ProtonVPN again.
There is an error during the installation process: ProtonVPNTap was not correctly installed.
The log mentions error 4153:
Error 4153. ProtonVPNTap mandatory prerequisite was not correctly installed.
MSI (s) (00!2C) [10:00:44:200]: Product: ProtonVPN – Error 4153. ProtonVPNTap mandatory prerequisite was not correctly installed.
CustomAction AI_VerifyPrereq returned actual error code 1603 (note this may not be 100% accurate if translation happened inside sandbox)
Action ended 10:00:44: AI_VerifyPrereq. Return value 3.
Action ended 10:00:44: INSTALL. Return value 3.
I’m assuming that worked for you as well?
I have installed the TAP from:
https://openvpn.net/community-downloads/
And deleted:
C:\Program Files (x86)\Proton Technologies\
C:\Users\USER\AppData\Local\ProtonVpn
C:\Users\USER\AppData\Roaming\ProtonVPN AG
Then the installation process could properly finish.
However, I still have the issue described in the OP: ProtonVPN silently crashes after I double-click on its shortcut on the desktop. I can see it happening by monitoring the task manager.
With the event viewer, I can see the errors. There are actually two of them (in French below).
Application : ProtonVPN.exe
Version du Framework : v4.0.30319
Description : le processus a été arrêté en raison d’une exception non gérée.
Informations sur l’exception : code d’exception c0000005, adresse d’exception 00007FF87CBDC416
Nom de l’application défaillante ProtonVPN.exe, version : 1.10.1.0, horodatage : 0x5d513a99
Nom du module défaillant : d3d9.dll, version : 10.0.18362.329, horodatage : 0x1ac9a115
Code d’exception : 0xc0000005
Décalage d’erreur : 0x00000000000ac416
ID du processus défaillant : 0x1310
Heure de début de l’application défaillante : 0x01d56ad54892c32e
Chemin d’accès de l’application défaillante : C:\Applis\ProtonVPN\ProtonVPN.exe
Chemin d’accès du module défaillant: C:\WINDOWS\SYSTEM32\d3d9.dll
ID de rapport : 320700bb-b94f-4d89-8875-4334bd6e303b
Interestingly, as mentioned in the OP, I had 3 recent Windows updates, notably KB4514359 (.Net Framework) and KB4515384 (Windows 10). The third update was about Flash Player, so I don’t suspect it.
I will try to uninstall the one about .NET.
