Desktop: CTRL-S in diagram editor does not save changes in spite of UI feedback

[SecureMedDev]

Describe the bug:

CTRL-S in the diagram editor seemingly saves your changes but effectively does not (see "To Reproduce" below).

Expected behaviour:

CTRL-S in the diagram editor should save your changes or at least the UI should not give the impression that it does.

Environment:

• Version: 2.6.0
• Platform: Desktop App
• OS: Windows

To Reproduce:

• Create a new model file.
• Add a new diagram.
• Close the model editing view.
• Click the diagram to edit it.
• Make some changes in the diagram.
• Hit CTRL-S on your keyboard.
• Observe the green "Threat model successfully saved" notification.
• Observe that the model's JSON file on your hard drive got a new modified timestamp.
• Observe that the model's JSON file does not include your changes (using cat or text editor).
• Close Threat-Dragon to see that you are not asked to discard any changes.
• Confirm again that your changes were not saved in the JSON file.
• Be happy that you just tested this and did not lose hours of work...

Declaration:

By submitting this issue you have:

• read the contribution guide and agree to the Code of Conduct
• not used agentic or generative AI in creating this bug report

[jgadsden]

thanks @SecureMedDev , hope that you did not lose hours of work

[lreading]

Hi @SecureMedDev - thanks again for the detailed report!

I'm going to use this issue as a parent issue for the related desktop save issues.

This specific bug affects at least v2.5.0 and v2.6.0 desktop clients for all operating systems

Temporary Workaround

Click the Save button at the top-right of the diagram after editing.
Do not rely on ctrl+s until we release a new patch version. 🙃

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I am working on a fix targeting v2.6.1. We've been chasing these desktop save bugs for a while. @SecureMedDev - the nuance of using ctrl+s to save finally made it click for me. Providing such a detailed report really made all the difference, so thank you - sincerely. <3

Root Cause
There are desktop-only code paths for saving rather than reusing the web save implementation.
Desktop-only code should be reserved for electron-specific behavior, not core functionality.
ctrl+s on desktop is one of the affected paths.
File > Save Model / Save Model As bug was fixed in v2.6.0, but did not address the ctrl+s path

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There was already a fix for some of the desktop-only save paths in the v2.6.0 release.

Bug / Version Matrix

Save Path	2.5.0	2.6.0	Note
In-diagram Save button	Pass	Pass	Standard VueJS save path, no related issues
Ctrl+S	Fail	Fail	This issue
File > Save Model	Fail	Pass	Fixed in #1437 / v2.6.0
File > Save Model As	Fail	Pass	Fixed in #1437 / v2.6.0
"Report" feature missing data after save	Fail	Fail after bad Ctrl+S	Downstream symptom, not the root cause

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Related issues

Issue	State	Status	Description
#1534	Open	Source of truth	ctrl+s says saved - changes not persisted in JSON
#1514	Closed in favor of this issue	Related symptom	Mitigated threat missing after save on desktop in v2.5.0
#1360	Closed	Fixed by #1437 in v2.6.0	File > Save Model / Save Model As failed to persist changes
#1154	Closed	Closed March 10, 2026 as not reproducible	Save did not persist threats
#1254	Closed	Related symptom	OneDrive save produced an almost empty file. ctrl+s was cited as a contributing factor. Save button worked as expected