Problem: “Unable to Initialize SteamAPI” error prompt after click on the game from Steam library. This error may caused by firewall, Comodo Internet Security or Steam beta client.
Content Summary
Solution 1: Add Exception list for related Game’s Executable in Firewall
Solution 2: Opt out of Steam Beta
Solution 3: Disable Auto-Containment on Comodo Internet Security
Solution 4: Reinstall Steam PC Client
Reference
Solution 1: Add Exception list for related Game’s Executable in Firewall
If you have third-party firewall active or Windows Defender Firewall turned on, it might be blocking the game’s executable from connecting to the Internet.
For Windows Firewall:
Step 1: Go to Start > Control Panel > Windows Firewall.
Step 2: Click Allow and app or feature through Windows Firewall option from the left side list of options.
Step 3: Locate the game’s entry on the list and check the boxes next to both Private and Public networks.
Step 4: Click OK and restart computer.
Solution 2: Opt out of Steam Beta
Step 1: Go to Start > Steam PC client.
Step 2: Click on Steam option > Settings > Account tab > Change button under Beta participation section.
Step 3: Click to open the drop-down menu, choose NOTE – Opt out of all beta programs option and Apply.
Step 4: Exit from Steam PC Client.
Step 5: Press Ctrl + Shift + Esc key combination to open Task Manager.
Step 6: Click on More detail, select Steam-related processes (such as Steam.exe, Steam Client Bootstrapper or GameOverlayUI.exe) one by one and choose the End task option.
Step 7: Locate Steam.exe executable and right click to open its properties.
Step 8: Go to Compatibility tab, check for Run this program as an administrator option and click Apply.
Step 9: Open Steam PC Client and try relaunching the game.
Solution 3: Disable Auto-Containment on Comodo Internet Security
Step 1: Open the Comodo Internet Security UI.
Step 2: Go to Settings > Security Settings > Advanced Protection > Containment > Auto-Containment.
Step 3: Uncheck Enable Auto-Containment option or locate the game’s executable from the list and turn off the slider under Enable Auto-containment option.
Step 4: Confirm the changes.
Solution 4: Reinstall Steam PC Client
Step 1: Open Steam Client.
Step 2: Go to Settings > Downloads > Steam Library Folders.
Step 3: Navigate to the file path stated in Steam Library Folders and find steamapps folder.
Step 4: Backup steamapps folder.
Step 5: Repeat the same process for all library folders.
Step 6: Go to Start > Control Panel > Uninstall a Program.
Step 7: Locate Steam entry on the list, click on it once.
Step 8: Click on Uninstall button and confirm any dialog boxes which may appear.
Step 9: Restart computer.
Step 10: Redownload Steam and run the downloaded executable on computer.
Step 11: Add the folders again as the Steam library folders.
Reference
Steam Community: [SOLVED] “Unable to Initialize Steam Api” After Latest Update
Community Beta for Bethesda.net: HELP-unable to initialize steam API error
Reddit r/Steam: How do you fix “unable to initialize steam api”?
