Overview#
Fusion is a large application that mixes local processing with cloud services, so a "crash" can mean several different things: the program closes, the interface freezes, one command hangs, the canvas turns black or glitches, or a design will not open. Each has different causes and different fixes. This page gives you a repeatable order of operations: protect your work, identify what kind of failure it is, apply the least destructive fix first, and escalate only if needed. Clearing caches and reinstalling are effective, but they should come after simpler checks.
Note: Autodesk's help documents the cache reset through the built-in Fusion Service Utility (Help > Support and Diagnostics > Service Utility), not through manual folder deletion. The help does not publish cache or log folder paths, so this page does not give them; use the utilities below, which open the right location for you.
Where to find it#
- Support and Diagnostics menu: on the Fusion Application Bar, click Help > Support and Diagnostics. It holds Annotate Log File, Diagnostic Log Files, Graphics Diagnostic, Service Utility and Report Performance Issue.
- Service Utility outside Fusion: Windows, start the app called Fusion Service Utility from the Start menu; Mac, start it from the Launchpad. It opens automatically if Fusion fails to launch twice in a row.
- Diagnostic logs: Diagnostic Log Files collects your logs into FusionDiagnosticLogs.zip; the dialog's Open File Location button shows where it was saved.
- Forums and service status: the Autodesk forums and status site (not part of the help mirror).
First, protect your work#
- Do not close the frozen window immediately. Give it two minutes; some operations such as heavy recomputes or cloud saves block the interface.
- Check the network. A hung Save may be a connectivity issue.
- Check recovery. After a crash, reopen Fusion and look for recovered changes (an automatic recovery prompt is not confirmed in Autodesk's documentation; Recovery Save is a documented command, Ctrl+Shift+S on Windows). If you get a recovered document, immediately Save As under a new name.
- Look at version history. Even if the latest changes are lost, earlier saved versions remain in the Data Panel under Version History. See the versioning page in Getting Started.
- Export a neutral copy. Once the design opens, export a STEP and an archive (.f3z) so you have a copy outside the cloud.
Classify the problem#
| Symptom | Likely area | First thing to try |
|---|---|---|
| Fusion closes at launch | Installation, graphics driver, corrupt local settings | Restart the computer, update the driver, clear the cache |
| Crash when opening one design | Corrupt document, external reference, or heavy design | Open an earlier version; open with "references off" if offered |
| Crash when running one command | A bug or a bad input | Try different inputs; roll back the timeline; check the forum |
| Freeze when orbiting | Graphics | Lower display settings; update the driver |
| Black or flickering canvas | Graphics driver | Switch graphics mode in Preferences; update or roll back the driver |
| Slow save or hang on save | Network or large file | Check network; save a copy; split the design |
| "Something went wrong" dialog | Service or sync | Check the status page; sign out and in |
| Missing toolbar icons | Corrupt UI settings | Reset the workspace or clear the cache |
| Crash on exit only | Cloud sync or plugin | Close, wait; disable add-ins |
Escalation ladder#
Follow these steps in order, stopping when the problem is fixed.
- Restart Fusion. Fully quit, including from the system tray or Dock, then reopen.
- Restart the computer. Clears stuck processes and GPU states.
- Update Fusion. Fusion normally updates itself on launch. A pending update, or an interrupted one, can cause odd behavior. Let it finish.
- Update the operating system and graphics driver. Use the manufacturer's installer. If the problem started after a driver update, roll back.
- Check hardware acceleration. On laptops, force the dedicated GPU. In Preferences, try the Performance graphics preset, and check Help > Support and Diagnostics > Graphics Diagnostic.
- Disable add-ins and scripts. Open the Scripts and Add-Ins manager (Shift+S) and stop any custom or third-party add-ins, then restart.
- Test with a new design. If a blank design works, the problem is your document. If it also fails, it is the application.
- Test with a different user account or machine. This separates a machine problem from an account problem.
- Clear the Fusion cache with the Service Utility Reset (below).
- Repair or reinstall Fusion (below).
- Contact support with logs: Gather System Information in the Service Utility, or Diagnostic Log Files (below).
Clearing the cache#
Autodesk lists these reasons to clear cached data: it fixes corrupted or stale app state (blank panels, missing icons, stuck sign-in), refreshes cached content after updates, add-in changes or driver changes, can improve stability and reduce long startups caused by a bloated cache, and frees disk space.
Step by step (Autodesk's documented procedure)#
- Save and sync everything first (general guidance: Reset clears sign-in credentials and settings).
- On the Fusion Application Bar, click Help > Support and Diagnostics > Service Utility. The Fusion Service Utility dialog opens.
- Quit Fusion, but keep the Service Utility dialog open.
- In the dialog, select Reset. A confirmation message appears.
- Click Yes, Proceed. Fusion closes and resets, then a dialog appears.
- Click Launch Fusion. The cached data is cleared and Fusion opens.
Per the Service Utility page, Reset clears sign-in credentials and the local cache and restores default application settings and preferences, so expect to sign in again.
Note: not confirmed in Autodesk's documentation: manual deletion or renaming of folders such as webdeploy, AppData\Autodesk or ~/Library/Application Support/Autodesk. Earlier drafts listed them; they were removed.
What cache clearing fixes and does not fix#
| Autodesk says it fixes | Does not fix (general guidance) |
|---|---|
| Corrupted or stale app state: blank panels, missing icons, stuck sign-in | A genuinely corrupt cloud file |
| Stale cached content after updates, add-in or driver changes | License entitlement problems |
| Bloated cache causing long startups | Hardware or driver faults |
| Disk space used by cached data | A bug in the current build |
Resetting preferences only#
The Preferences dialog has Restore Defaults at its lower left, which resets all preferences. Service Utility Reset also restores defaults along with clearing the cache. Note custom shortcuts and toolbar changes first.
Repair and reinstall#
The Service Utility menu documents: Contact Support, Gather System Information, Network Diagnostics (checks key domains required for Fusion and Autodesk services), Repair (verifies and repairs the installation without removing designs), Reset, Uninstall (a lightweight uninstall; for a clean uninstall Autodesk says to follow the manual uninstall steps), Launch Fusion, and Close Fusion Service Utility.
- Back up first: export archives of important designs.
- Try Repair before anything else.
- If you must reinstall, uninstall, download the installer from Autodesk, reinstall and sign in. General guidance: cloud data is not removed by reinstalling.
Specific common problems#
Design will not open#
- Try opening a previous version from the Data Panel.
- Open from the browser version or web client to check whether the file is healthy (the Fusion web client is not included with personal use or trial).
- Check that referenced components are accessible. A missing external reference can block opening or show warnings.
- Make a copy of the project folder item and open the copy.
Canvas glitches (black, striped, transparent faces)#
- Update or roll back the graphics driver.
- Try the alternative graphics setting in Preferences.
- Disable shadows and reflections.
- On a hybrid-graphics laptop, set the high-performance GPU.
Command crashes#
- Note the exact inputs. Try with simpler geometry.
- Roll back the timeline and re-apply.
- Check the forum for the command name plus "crash".
- File a bug with a minimal file (below).
Autosave and recovery#
The shortcuts reference lists a Recovery Save command (Ctrl+Shift+S, or Command+Shift+S on macOS). The documentation does not describe an automatic recovery prompt after a crash. Check version history if nothing is recovered. Do not rely on recovery; save often, and use milestones.
Reporting a bug#
- Reproduce. Find the minimal steps that cause the problem.
- Make a minimal file. Remove everything unrelated. Save it as an archive.
- Collect details. Fusion version (Help > About), operating system, GPU and driver. Help > Support and Diagnostics > Graphics Diagnostic shows GPU device, RAM, driver API (and on Windows driver version and date) and has Copy to Clipboard.
- Annotate the log. Help > Support and Diagnostics > Annotate Log File adds a message (maximum 360 characters) to the diagnostic log, for example "Reproducing the issue now". Then use Diagnostic Log Files to collect FusionDiagnosticLogs.zip for support.
- For performance problems, use Report Performance Issue: agree to the terms, Start gathering data, demonstrate the workflow (10 minute recorder limit; no audio or video), Stop data gathering, fill out the questionnaire and Submit. A report ID is generated. To capture startup, start collecting, close Fusion, restart it, record the startup, then fill out the questionnaire.
- Post on the Autodesk forum, or use Get Support / the Service Utility Contact Support option.
Tip: Screen recordings help engineers more than descriptions. Keep the recording short and show the exact click sequence.
Options reference#
| Option | What it does | Notes/default |
|---|---|---|
| Recovery Save | Documented save command | Ctrl+Shift+S / Command+Shift+S |
| Version History | Restores earlier saved versions | Data Panel |
| Save As | Creates an independent copy | Use after recovery |
| Service Utility > Reset | Clears sign-in credentials and local cache, restores default settings | Help > Support and Diagnostics |
| Service Utility > Repair | Repairs installation without removing designs | |
| Diagnostic Log Files | Collects logs into FusionDiagnosticLogs.zip | Help > Support and Diagnostics |
| Add-Ins manager | Disables custom scripts and add-ins | Shift+S |
| Annotate Log File | Adds a message (max 360 characters) to the log | Help > Support and Diagnostics |
| Status page | Shows cloud outages | Check before troubleshooting |
Tips and pitfalls#
Tip: Save a copy under a new name before attempting a risky operation such as a large pattern or a Combine on complex bodies. If it hangs, you can discard the session without losing the base design.
Warning: Avoid force-quitting during a cloud save. If you must, check Version History afterward to ensure the last version is intact.
Warning: Antivirus and corporate security software can interfere with Fusion's installer and cache. Ask your IT team to allow Fusion and Autodesk services if you see repeated install or sync failures.
Tip: Keep a text file of your Fusion and driver versions when things work. It tells you what changed when they stop.
Practice exercise#
- Open Help > Support and Diagnostics and look at each entry (do not click Reset).
- Open Help > About and record your version, then run Graphics Diagnostic and Copy to Clipboard.
- Find the Version History of a design in the Data Panel and open an earlier version.
- Write the escalation ladder from this page as a personal checklist.
Expected result: you can name the first three steps you would take after a crash and know where the diagnostic tools live.
Related#
- Performance tuning (this section)
- Sign-in, licensing, and sync problems (this section)
- Installing Fusion (Getting Started)
- Versioning and milestones (Getting Started)