"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