Re: "Please wait while we install/open the partner application" SOLUTION/FIX

@szy-rocks  Have you tried closing the process I mentioned in the above post? If that doesn't work, try reinstalling the EA app.
You can also try launching the linking exe yourself, on the shortcut of EA --> Right Click --> Open file location and try to open as admin the app "Link2EA", added a screenshot of it.

@szy-rocks If those steps do not work, can you please run through the following so we make sure everything is updated?

Nvidia

• Try the NVIDIA PhysX Legacy System
• Restart the PC.
• Test.

Delete Windows Temp Files

• Press the Windows key + R, go into the file explorer
• Type in %temp%, and hit Enter
• Delete everything it allows you to delete
• Reboot the PC

• EA App's Cache (Top Left Menu > Help > App Recovery)
• Repair/Verify your game based on which client you are launching from
• EA App - Repair (My Collection > Tile Dots > Repair)
• Steam - Verify in your library
• Run the System File Checker tool then Check for Windows and GPU updates 
• Uninstall VC++ from the control panel
• Install/Repair your VC++ files for the game (Microsoft VC++ Link)
• Download and update DirectX

If these do not work, try the following:

• Try a Clean Boot
• Try Safe Mode with Networking
• Try a new Windows Account

@EA_ShepardI've tried all of the above and nothing works. I've reinstalled these apps about 20 times an I still can't install the game at all.

Edit: I have tried installing in two separate PCs and it refuses to work. not sure what to do here.. 

The answer is to not use the Epic Games installer and use the EA installer. The Epic Games installer is pure, unadulterated balls.