How to get rid of the error messages "Purchase pending" and "Purchase failed" on Steam

PURCHASE WINDOW IS HIDDEN

After clicking the "Buy and download" or "Buy" buttons, a window will open. 

If the Steam overlay doesn't appear after clicking the "Buy and download" or "Buy" buttons

• Press the ALT + TAB keys to switch between application-level windows
• Make sure the purchase window isn't hidden under the game window

 

ENABLE STEAM OVERLAY

If the purchase window isn't hidden under the game window and you receive the message "Purchase pending" immediately upon clicking the "Buy and download" or "Buy" buttons, double-check that the Steam Overlay is enabled in both the Steam setting and the game's properties and that the default shortcut keys do not conflict with in-game keybindings.

1. Open your Steam client.
2. In the top left corner of the screen, click on Steam 
3. Select Settings
4. Click on the In-Game tab
5. Check “ Enable the Steam Overlay while in-game. ”
6. From there you can also change the Overlay shortcut keys.
7. Go to Library and right-click on Microsoft Flight Simulator.
8. Select Properties
9. Stay on the "General" tab and check “Enable the Steam Overlay while in-game” 

RUN STEAM.EXE AND STEAMOVERLAYUI.EXE AS ADMINISTRATOR

If you receive the error message "Purchase failed" immediately upon clicking on the "Buy" button or the "Buy & Download" button

1. Run Steam.exe as administrator

1. Close Steam
2. Navigate to the Steam installation folder. By default, Steam is installed at the following location: C:\Program Files (x86)\Steam
3. Right-click on steam.exe
4. Click on Properties
5. Open the Compatibility tab
6. Check the box "Run this program as an administrator"
7. Click Apply to save the settings

2. Run SteamOverlayUI.exe

1. Right-click on GameOverlayUI.exe 
2. Select Properties
3. Go to the Compatibility tab, check the box "Run this program as an administrator" and click Apply.

The Steam Overlay should now open correctly in-game. 

STEAM CLIENT

If the Steam Overlay still doesn't work after following the steps above, go to Steam Community Overlay

or contact Steam Support for further assistance with the Steam Overlay.