[Windows] ChatGPT.exe remains running but no GUI appears — CUA Runtime staging/relocation anomaly observed

What version of the Codex App are you using (From “About Codex” dialog)?

26.831.2377.0

What subscription do you have?

Free

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Problem

On Windows, the Codex/ChatGPT desktop application can start its main ChatGPT.exe process but fail to create a visible desktop window.

In the affected state I observed:

• ChatGPT.exe main process was running and responsive.
• MainWindowHandle = 0.
• MainWindowTitle was empty.
• No ChatGPT.exe --type=renderer process was observed.
• Crashpad, GPU, and utility-related processes could still be present.
• Windows/AppX activation did not show an obvious failure.
• The local CUA runtime contained multiple .staging-* directories.
• In affected staging states, node.exe was present while node_repl.exe was missing.
• The affected staging directories contained substantially fewer files than the complete packaged runtime.

The complete packaged cua_node runtime contained 4684 files.

The packaged runtime manifest specified:

• platform: windows
• architecture: x64
• target: windows-x64
• Node version: 24.19.0
• node_path: bin/node.exe
• node_repl_path: bin/node_repl.exe

The SHA-256 of the packaged node.exe was:

5F8010B905B9A36274172010091725811047F2C0DC2540179287D4BB2D938270

An older local runtime contained a different node.exe with SHA-256:

B964BDD09E3A526A68EAB76FE8DEECC3DFB4D3398118F66DD9BDD185CDA190A6

The packaged node_repl.exe also reported:

Compatibility Level: Application Protected

when inspected with cipher /c.

I then stopped the ChatGPT-related processes and restored the complete packaged CUA runtime. After restoration, the runtime contained all 4684 files, including both node.exe and node_repl.exe.

After restarting ChatGPT.exe:

1. The Codex desktop GUI appeared normally.
2. Switching from Codex to ChatGPT displayed the ChatGPT GUI normally.

The observed evidence suggests a strong association between the CUA runtime staging/integrity state and the headless startup behavior. However, this report does not claim that the complete internal causal mechanism has been proven.

In particular, the following remain unknown:

• why the runtime relocation/staging process entered the incomplete state;
• which specific file operation failed first;
• why the Renderer process was not created;
• whether the missing node_repl.exe was the direct blocking factor;
• whether Windows Application Protected behavior was the direct trigger;
• the complete internal causal chain between runtime state and GUI creation.

What steps can reproduce the bug?

Observed startup sequence

This report is based on an actual affected installation. The sequence below describes the observed failure state; I do not currently claim that the issue is deterministically reproducible on every installation.

1. Launch the installed Codex/ChatGPT desktop application.
2. ChatGPT.exe starts and remains running.
3. The main process remains responsive.
4. MainWindowHandle remains 0 and no usable desktop window appears.
5. Querying the process tree shows no ChatGPT.exe --type=renderer process.
6. Windows/AppX activation records do not show an obvious activation failure.
7. Inspect %LOCALAPPDATA%\OpenAI\Codex\runtimes\cua_node\.
8. Multiple .staging-* directories are observed.
9. In affected staging states, node.exe is present while node_repl.exe is absent, and the staging directory is substantially incomplete compared with the packaged runtime.
10. The staging state changes dynamically during startup, with staging directories being created, modified, and cleaned up.
11. After stopping the ChatGPT-related processes, the complete packaged CUA runtime was restored.
12. The restored runtime contained 4684 files, including node.exe and node_repl.exe.
13. Restarting ChatGPT.exe then resulted in a normal Codex GUI.
14. Switching from Codex to ChatGPT also resulted in a normal ChatGPT GUI.

No session ID, authentication token, or API credential is required to describe this startup failure, and none is included in this report.

What is the expected behavior?

Launching the Codex/ChatGPT desktop application should create a visible and usable desktop window.

The main process should successfully proceed through its normal startup sequence, including creation of the required renderer and runtime components, rather than remaining as a background process with MainWindowHandle = 0.

Additional information

Additional information

Observed workaround

As part of the investigation, I stopped the ChatGPT-related processes and restored the complete packaged cua_node runtime, including both bin/node.exe and bin/node_repl.exe.

After the runtime was restored to its complete 4684-file state:

1. Restarting ChatGPT.exe resulted in a normal Codex desktop GUI.
2. Switching from Codex to ChatGPT also resulted in a normal ChatGPT GUI.

This workaround was effective in this affected installation. I am reporting it as an observed recovery procedure, not as a definitive root-cause fix.

External comparison

During the investigation, I found several public Codex issues describing related Windows desktop startup behavior, including:

• #41540 — Windows Application Protected node_repl.exe relocation failure associated with headless startup.
• #41654 — Windows Codex Desktop runtime relocation/staging failure involving incomplete cua_node contents and missing node_repl.exe.
• #42669 — Windows Codex Desktop processes launching without a visible window, with a different reported failure involving Artifact Session host / Unix-socket transport.

These issues are included as independent external comparisons only. I am not claiming that these incidents are identical or that they establish the root cause of this particular installation.

Diagnostic interpretation

The main observation from this investigation is that a desktop application can successfully reach the main-process stage while failing to produce the expected Window and Renderer stages.

The observed state can be summarized as:

AppX: OK
Activation: OK
Main Process: RUNNING
Window: ABSENT
Renderer: ABSENT
CUA Runtime: STAGING / INCOMPLETE
Runtime Integrity: INCOMPLETE
Runtime Restore: SUCCESSFUL
GUI: RESTORED

This suggests that checking only whether ChatGPT.exe is running is insufficient to diagnose this class of desktop startup failure.

I am reporting the runtime staging/integrity observations as an independently investigated failure mode, rather than claiming a definitive internal root cause.

Start with %LOCALAPPDATA%\OpenAI\Codex\runtimes\cua_node\ and compare the .staging-* directories with the complete packaged runtime and its manifest. Check the startup sequence around ChatGPT.exe, MainWindowHandle, and renderer creation, using the reported 4684-file state and node.exe/node_repl.exe presence as evidence. Done means identifying the failing staging or relocation step and restoring normal window and renderer creation without manual runtime restoration.