The affected user encounters the assertion failed error when he tries to join an online game server. The issue is not specific to a particular map of the game. Before proceeding with the solutions, make sure the Steam servers are up and running.
Solution 1: Launch the Game Directly from the Installation Directory
You may encounter the error at hand if the Steam client is having trouble in launching the game or the shortcut of the game is corrupt. In this context, launching the game directly from the installation directory may solve the problem.
Solution 2: Launch Steam/Ark With Administrator Privileges
In the recent version of Windows, Microsoft has quite impressively enhanced privacy and security features of its OS. One of such features is protecting vital system resources by UAC. You may encounter the error under discussion if the game/Steam could not access an essential system resource due to UAC restrictions. In this context, launching the Steam/game as an administrator may solve the problem.
Solution 3: Verify the Integrity of the Game Files of Ark
You may encounter the error under discussion if the game files of Ark, essential for the operation of the game, are corrupt. In this context, verifying the integrity of the game files may solve the problem. This process will check the game files against the server version of the files, and if there are any missing/corrupted files, then the files will be replaced with fresh ones.
Solution 4: Unsubscribe from All the Mods and Reinstall the Maps/DLC
Players can add or modify the content of the game through Mods available through Steam Workshop. You may encounter the error under discussion if any of the mods related to the game are corrupted or is incompatible with the version of the game. In this case, unsubscribing from all the mods and reinstalling the related DLCs/maps may solve the problem.
Solution 5: Reinstall the Steam Client
If nothing has worked for you, then most probably the installation of the Steam client is corrupt and is the root cause of the issue under discussion. In this scenario, reinstalling the Steam client may solve the problem.
Fix: Ark Failed to Open Descriptor FileFix: Failed to Install Mod Map in ARKFix: ARK Unable to Query Server Info for InviteFix: ARK Fatal Error
