TL;DR
Postman crashes on startup, loses sync, and corrupts collection data often enough that entire Reddit threads are dedicated to each problem. This guide covers the root cause and fix for the most common issues, including Fedora crashes, VS Code extension failures, and collection sync conflicts. Where the fix is a workaround rather than a real solution, Apidog is noted as an alternative that doesn’t have the underlying issue.
Apidog is a free, all-in-one API development platform. It uses local-first storage by default, which eliminates cloud sync conflicts and keeps your collections intact across sessions. Try Apidog free, no credit card required.
Introduction
Postman is a mature product, but that doesn’t mean it’s stable. As the app has grown to include Flows, AI features, monitoring, and governance tooling, the attack surface for bugs has expanded. Developers report crashes on specific Linux distributions, silent data loss from sync conflicts, and VS Code extension hangs that require a full IDE restart.
Most of these problems have fixes. Some are one-line command-line patches. Others require changing how you structure your workflow. A few are genuinely unresolved and the best answer is a different tool.
This guide covers each major issue category, explains why it happens, and gives you the fastest path to resolution.
Postman crashes on startup (Fedora and Linux)
Root cause
Postman ships as an Electron app. On Fedora and some other Linux distributions, a conflict between Postman’s bundled Chromium sandbox and the host kernel’s seccomp rules causes the process to crash before the UI loads. This became especially common after Fedora 37 and 38 tightened their default sandbox policies.
The crash often produces no visible error. The app simply closes. In terminal output, you may see:
[FATAL:zygote_host_impl_linux.cc] Check failed: sandbox status is kSandboxLinux
Short-term fix
Launch Postman with the sandbox disabled:
postman --no-sandbox
To make this persistent, edit the desktop launcher file at /usr/share/applications/postman.desktop and add --no-sandbox to the Exec line.
Important caveat: Disabling the Chromium sandbox reduces the security isolation of the app. This is acceptable on a developer workstation where you control the environment. It’s not appropriate for shared or production systems.
Why Apidog avoids this issue
Apidog’s Linux distribution is packaged differently and doesn’t rely on Chromium sandbox policies for core functionality. On Fedora 38 and 39, Apidog opens without the --no-sandbox workaround.
Postman VS Code extension crash
Root cause
The Postman VS Code extension embeds a separate Electron runtime alongside VS Code’s own Electron layer. When both are running simultaneously and VS Code updates its version, a version mismatch between the two Electron instances can cause the extension to hang or crash VS Code entirely.
This commonly happens after VS Code auto-updates. Developers report the extension freezing at the “Loading workspace” screen, consuming 100% CPU, or causing VS Code to become unresponsive.
Short-term fix
- Open VS Code’s Extensions panel (
Ctrl+Shift+X). - Find the Postman extension and click “Disable.”
- Restart VS Code.
- Re-enable the extension.
If that doesn’t work, fully uninstall and reinstall the extension:
code --uninstall-extension Postman.postman-for-vscode
code --install-extension Postman.postman-for-vscode
If the crash persists after reinstall, check whether VS Code’s version jumped more than one minor version. Rolling back VS Code one version and waiting for the Postman extension to update is sometimes the only path.
Longer-term fix
Use the Postman desktop app alongside VS Code rather than the extension. The extension is convenient but adds instability. Most developers find the desktop app more reliable for complex collection work.
Why Apidog avoids this issue
Apidog’s VS Code extension uses the VS Code extension API rather than embedding a separate Electron runtime. It doesn’t create a competing Electron process, which eliminates this class of version conflict.
Postman sync not working
Root cause
Postman sync failures usually fall into one of three categories:
Auth token expiry: Postman’s sync token expires after a period of inactivity. The app sometimes fails silently instead of prompting re-authentication.
Workspace ID mismatch: If you’ve been added to a new workspace while the app is open, the local client doesn’t always pick up the new workspace ID, causing sync to fail for that workspace.
Network proxy interference: Corporate proxies that perform SSL inspection can break Postman’s sync because Postman pins its own certificate chain. The proxy’s injected certificate doesn’t match, and sync silently fails.
Fixes by category
For auth token expiry:
- Sign out of Postman and sign back in. This forces a fresh token.
For workspace ID mismatch:
- Close Postman entirely.
- Open a terminal and clear the sync cache:
- macOS:
rm -rf ~/Library/Application\ Support/Postman/IndexedDB - Linux:
rm -rf ~/.config/Postman/IndexedDB - Windows:
%APPDATA%\Postman\IndexedDB - Reopen Postman and let it re-sync from the server.
For proxy interference:
- Add Postman to your proxy’s SSL inspection bypass list.
- Alternatively, configure Postman’s proxy settings under Settings > Proxy to route through your corporate proxy explicitly.
Warning: Clearing the IndexedDB cache will force a full re-sync. Make sure your collections are backed up to the Postman cloud or exported as JSON before doing this.
Collection sync conflicts
Root cause
Postman uses an optimistic concurrency model for collection sync. When two team members edit the same collection at the same time, or when the same user edits on two machines without syncing in between, Postman resolves conflicts by keeping the most recently synced version. The other version is silently discarded.
There is no merge. There is no conflict dialog. Your changes can disappear without warning if someone else’s sync lands first.
Short-term fix
Before making significant changes to a shared collection:
- Export the collection as a JSON backup (right-click > Export).
- Make your changes.
- Export again after saving.
If you discover your changes were overwritten:
- Go to the collection in your workspace.
- Click the three-dot menu and select “View changelog.”
- Identify the version before the overwrite and restore it.
Note: changelog access requires a paid Postman plan. On the free tier, you have no recovery option once a sync overwrites your work.
Why Apidog avoids this issue
Apidog stores collections locally by default. Cloud sync is opt-in. When you do use cloud sync, Apidog shows explicit conflict resolution prompts rather than silently overwriting. You choose which version wins. Nothing disappears without your input.
Postman app is slow or freezing after update
Root cause
Postman’s Electron app loads a significant amount of JavaScript at startup, including the Flows canvas, AI components, and workspace management layers. After updates, cached assets sometimes conflict with the new version, causing extended load times or freezes at the splash screen.
Fix
Clear the app cache:
- macOS:
rm -rf ~/Library/Application\ Support/Postman/Cache - Linux:
rm -rf ~/.config/Postman/Cache - Windows:
%APPDATA%\Postman\Cache
Then restart Postman. The first launch after cache clearing will be slower as assets rebuild. Subsequent launches should return to normal speed.
If slowness persists, check whether your collections are very large. Collections with thousands of requests in a single workspace can cause significant UI lag in Postman’s tree view.
Environment variables disappearing after restart
Root cause
Postman separates “initial value” from “current value” for environment variables. The current value is local to your machine and not synced to the cloud. If you set a variable’s current value during a session and then the app crashes, or if you install Postman on a new machine, those current values are gone.
This trips up developers who share environments with teammates. You share the environment, but the current values don’t travel with it.
Fix
For variables you want persisted and shared:
- Set the “Initial value” in the environment editor, not just the current value.
- The initial value syncs to the cloud and is visible to teammates.
For sensitive variables like API keys:
- Use current value only and document that teammates need to set their own.
- Never put secrets in initial value since that syncs to Postman’s servers.
FAQ
Why does Postman crash on Fedora but not on Ubuntu?Fedora applies stricter default kernel security policies than Ubuntu. Postman’s bundled Chromium sandbox makes assumptions about the host kernel that Fedora’s security settings don’t allow. Ubuntu’s more permissive defaults let the sandbox work without conflict.
Can I recover a collection that was overwritten by sync?On paid Postman plans, the changelog lets you restore a previous version. On free plans, you can only recover if you exported a backup before the overwrite happened. This is one of the most frustrating limitations of Postman’s free tier.
Is Postman’s VS Code extension worth using?For light use, yes. For complex collection work or heavy test scripts, the desktop app is more stable. The extension is prone to version conflicts after VS Code updates.
Does clearing the IndexedDB cache delete my collections?Collections stored in Postman’s cloud are not affected. The IndexedDB cache is a local index of cloud data. After clearing, Postman rebuilds it from the cloud. Collections that exist only locally and were not synced would be lost, which is why you should export before clearing.
How does Apidog handle team collaboration differently?Apidog stores all data locally and syncs only when you explicitly share or publish to a team project. Conflicts are surfaced as explicit prompts. There’s no silent overwrite behavior.
Is there a way to use Postman offline?Yes, but with limits. The Postman desktop app works offline for request sending and collection editing. Features that depend on Postman’s cloud, like sync, monitors, and shared environments, require a connection.
Postman’s issues are fixable in most cases, but many of the fixes are workarounds for architectural decisions that won’t change. If you’re spending more time managing Postman than testing APIs, that’s a signal worth paying attention to.
