The Mound Omen of Cthulhu Crashing: Fixes for Startup and LowLevelFatalError

Fix The Mound Omen of Cthulhu crashing with display, driver, file, and Unreal Engine troubleshooting steps.

Start With the Most Likely Display Fix

Nothing kills an expedition faster than the mound omen of cthulhu crashing before you even reach the main menu. The issue matters because a startup crash can look like a broken installation, even when the actual cause is a temporary conflict between the game, Windows display settings, and an external monitor. If the mound omen of cthulhu crashing happens immediately after launch—particularly on a laptop connected to a monitor—test your display setup before reinstalling everything.

Community reports point to a specific pattern: some players received an Unreal Engine LowLevelFatalError involving D3D12 viewport creation. In those player experiences, the game launched successfully when the laptop’s built-in display was active during startup or when Windows used that screen as the primary display.

This does not prove every crash has the same cause. However, it is a fast, low-risk test that may save a great deal of time.

What you see	Most likely area to test first	Why it can matter
Crash immediately after clicking Play	External monitor and primary-display setting	The game may fail while initializing its first display viewport
`LowLevelFatalError` mentioning `D3D12RHI` or `Viewport`	Display configuration, GPU driver, saved settings	The error occurs during DirectX 12 rendering setup
Game worked yesterday but crashes today	Monitor connection, resolution, GPU update, corrupted config	A hardware or settings change may have altered startup behavior
Crash only while laptop lid is closed	Active-display detection	The game may be trying to initialize on a display state it does not handle correctly
Crash after a graphics setting change	Local game configuration files	An unsupported or invalid resolution can persist between launches

Quick display test for laptop players

Follow these steps in order:

Disconnect the external monitor, or turn it off.
Open the laptop lid and make sure its internal screen is active.
In Windows, set the laptop panel as the primary display.
Launch the game and wait until you reach the main menu.
Reconnect the monitor if needed.

A community report described success after changing the primary display, launching the game, and only then reconnecting the secondary monitor. Another player reported that keeping the laptop screen open until the loading screen appeared prevented the crash.

Display setup	Test to perform	Expected result if display initialization is the problem
Laptop closed, external monitor only	Open the lid and launch with both screens active	Game gets past startup
Two monitors, external display is primary	Make laptop panel primary temporarily	Game launches normally
Dock or HDMI adapter connected	Disconnect dock/adapter for one launch	Startup crash disappears
4K monitor connected	Launch at the laptop’s native display first	Game creates a stable initial viewport
Monitor reconnects after launch	Reconnect at the main menu	Game may continue running normally

For the latest storefront information and announcements, check The Mound: Omen of Cthulhu on Steam.

Use This Troubleshooting Order Before Reinstalling

When the mound omen of cthulhu crashing persists, avoid changing ten settings at once. A controlled process helps identify what worked and prevents unnecessary file loss.

Start with the least disruptive fixes. Verify files and update drivers before deleting local configuration data. If you delete the game’s local folder, back up anything important first because local folders can include settings, logs, and potentially save-related data depending on how the game handles synchronization.

Priority	Fix	How to do it	Risk level
1	Restart Windows	Perform a full restart, not just sleep or hibernate	None
2	Test one display	Disconnect extra monitors and launch with the laptop panel active	None
3	Set the primary monitor	Go to Settings > System > Display and select the intended main screen	None
4	Verify game files	Steam Library > game Properties > Installed Files > Verify integrity	Low
5	Update GPU driver	Use NVIDIA App, AMD Software, or Intel’s official driver tool	Low
6	Disable overlays temporarily	Turn off Discord, Steam, GeForce, Xbox Game Bar, and monitoring overlays	Low
7	Reset local settings	Rename the local game folder rather than immediately deleting it	Moderate
8	Reinstall the game	Use only after simpler tests fail	Moderate

Verify files correctly

Steam’s file verification checks whether installed files match the version Steam expects. It can replace missing or damaged files, but it will not necessarily fix a bad resolution setting stored in your Windows user profile.

To verify the installation:

Open Steam and select Library.
Right-click The Mound: Omen of Cthulhu.
Choose Properties.
Open Installed Files.
Select Verify integrity of game files.
Wait for Steam to complete the check, then restart the PC before testing again.

If Steam finds no problem and the crash still happens at the same instant, return to display and configuration troubleshooting rather than repeating the verification process.

Why LowLevelFatalError and D3D12 Crashes Can Happen

A LowLevelFatalError is an Unreal Engine crash message rather than a precise diagnosis. It often means the game encountered a failure while communicating with a graphics API, driver, GPU, or display output. The wording can be intimidating, but it does not automatically mean your graphics card is defective.

Community reports for the mound omen of cthulhu crashing included D3D12-related lines, viewport references, and an 80004004 error. Those reports appeared on systems with different display resolutions, including 1080p and 4K, which is another reason to treat display initialization as a troubleshooting lead rather than a confirmed universal bug.

Error clue	What it usually relates to	Practical response
`D3D12RHI`	DirectX 12 rendering interface	Update GPU driver and eliminate display conflicts
`D3D12Viewport`	Window, resolution, monitor, or fullscreen initialization	Change primary monitor and reset display settings
`RHIThread`	Unreal Engine rendering hardware interface thread	Check drivers, overlays, and graphics configuration
`Viewport` with a resolution listed	The game was creating a display output	Test a different active screen or lower initial resolution
Crash on startup but stable after launch	Initialization rather than sustained GPU load	Use the monitor workaround and preserve stable settings

Do not assume that lowering every graphics option is the answer. A startup viewport crash may occur before the game has rendered a demanding scene. In that case, changing which monitor is active can be more effective than reducing texture quality or resolution scale.

Reset Saved Graphics Settings Safely

If a monitor workaround helps once but the mound omen of cthulhu crashing returns, a saved resolution, refresh-rate, or window-mode setting may be contributing to the problem.

One community suggestion was to remove the game’s folder under AppData > Local > TheMound. A safer first approach is to rename the folder, which preserves a rollback copy. Windows will often create a new configuration folder the next time the game launches.

Back up before changing local files

Press Windows + R.
Enter %LOCALAPPDATA%.
Look for a folder named TheMound.
Rename it to something like TheMound-backup.
Launch the game with one active display.
If the game works, reconfigure graphics settings gradually.

Local-folder action	What it does	When to use it
Rename the folder	Forces the game to generate fresh settings while keeping a backup	Best first reset method
Delete only config files	May preserve other local data, but requires knowing file structure	Advanced users
Delete the entire local folder	Fully clears local settings and logs	Only after a backup
Restore the backup folder	Returns prior settings if the reset does not help	If the test fails
Check cloud sync status	Helps avoid confusion over restored settings or saves	Before and after changes

After resetting, use conservative startup settings until the game proves stable:

Setting	Safer starting choice	Why
Display mode	Borderless or windowed, if available	Can reduce exclusive-fullscreen conflicts
Resolution	Native resolution of the active primary display	Avoids mismatched startup output
Refresh rate	Default monitor refresh rate	Reduces unusual display-mode switching
HDR	Off for the initial test	Removes another display-handshake variable
Overlays	Disabled temporarily	Helps rule out hook or injection conflicts
Multiple displays	One active display for launch	Simplifies viewport detection

Once the game launches consistently, re-enable features one at a time. For example, reconnect the second monitor first, then turn on an overlay, then test HDR. That method makes it clear which change caused instability if the crash returns.

Update Drivers and Remove Common Conflicts

Outdated drivers can cause the mound omen of cthulhu crashing, but “updated” does not always mean “cleanly updated.” Laptop players should also make sure the game is using the dedicated GPU rather than an integrated graphics processor when one is available.

For NVIDIA laptops, open Windows Settings > System > Display > Graphics, add the game executable if necessary, select Options, and choose High performance. AMD and Intel users can use the same Windows graphics-preference menu, along with their manufacturer’s control software.

Potential conflict	Symptoms	Test or fix
Old or damaged GPU driver	Startup crash, black screen, DirectX error	Install the current driver from the GPU manufacturer
Integrated GPU selected	Poor performance or unstable launch on laptops	Set the game to High Performance in Windows Graphics settings
Discord or recording overlay	Crash during startup or after loading	Disable overlays temporarily
GPU monitoring tools	Rendering initialization failure in some games	Close monitoring, overclocking, or frame-limiter utilities
Remote desktop session	Wrong GPU or virtual display behavior	Launch locally on the primary machine
Windows updates pending	Driver and DirectX compatibility issues	Install updates and restart

If you recently updated a graphics driver and the game became unstable immediately afterward, consider a clean reinstall of that driver using the manufacturer’s official installation option. Avoid downloading drivers from unofficial sites.

When to Contact Support Instead of Continuing to Test

If the mound omen of cthulhu crashing continues after a single-display launch, file verification, driver update, and local-settings reset, collect useful information before contacting support. A clear report makes it easier for developers to identify a repeatable issue.

Include the following:

Your CPU, GPU, RAM, and Windows version
Whether you are on a desktop or laptop
Monitor model, resolution, refresh rate, and connection type
Whether the laptop lid was open or closed
The exact error message or screenshot
Whether the crash occurs before logos, at the loading screen, or in gameplay
Steps that consistently reproduce the crash
Whether the issue changes when only one display is active

Support-report detail	Why developers need it
Full error text	Identifies the game subsystem that failed
Display arrangement	Can reveal multi-monitor or docking issues
GPU driver version	Helps compare failures across driver releases
Game build and Steam branch	Confirms the exact version being tested
Reproduction steps	Lets QA attempt the same scenario
Crash logs, if requested	Provides technical context beyond the on-screen message

The important takeaway from current community reports is simple: do not overlook your monitor setup. Reinstalling may not help if Windows is still presenting the same problematic display arrangement at launch.

FAQ

Why is the mound omen of cthulhu crashing on startup with LowLevelFatalError?

Player experiences suggest that some startup crashes are related to DirectX 12 viewport initialization, especially on laptops using an external monitor. Launch with the laptop display active, make it the primary display, and test with the second monitor disconnected.

Can I reconnect my external monitor after the game starts?

Community reports indicate that some players could reconnect their monitor after reaching the main menu without another crash. Test this carefully, since results can vary by laptop, driver, dock, and monitor configuration.

Will verifying Steam files fix the crash?

It can fix missing or corrupted installation files, so it is a worthwhile early step. However, verification may not reset stored graphics settings, display preferences, or a driver-related problem.

Should I delete the AppData local folder?

Try renaming %LOCALAPPDATA%\TheMound first. This gives the game a fresh settings folder while preserving a backup you can restore if needed.