Lens reports failures where it can — an in-page toast when a content script can run, and the toolbar icon badge when one cannot.
1. This page cannot be captured
Chrome forbids extensions from running on some pages, and no extension can work around it.
- chrome:// and about: pages, including New Tab and Settings
- The Chrome Web Store
- devtools:// and view-source: pages
- Other extensions' pages
- The built-in PDF viewer
- file:// URLs, unless you enable Allow access to file URLs for Lens on chrome://extensions
On these pages the toolbar icon shows a red ! with the reason in its tooltip, because a toast cannot be drawn.
2. The recording came out blank
Tab capture succeeds on protected video but returns solid black — sites using DRM, such as YouTube and Netflix, are excluded from capture by design. Lens samples the recorded frames and warns you when they look blank, but still opens the converter so you can judge for yourself.
If a whole page records black, the page is blocking capture. If only a video player area is black, that player is protected and the rest of the page is fine.
3. Captures are going to Downloads instead of my folder
Folder access has lapsed. Open the popup: the folder row shows access lost and a Reconnect button. One click fixes it.
This happens because re-granting folder access requires a click, and the extension's background worker never has one — so it cannot recover on its own. See Projects and folders.
4. A capture saved but is not in the timeline
The file was written but project_metadata.json could not be updated. The save toast says so explicitly. Two causes:
- Write metadata file is switched off in Settings — turn it back on.
- The metadata file could not be written, usually a permission problem on the folder. Reconnect the folder.
The timeline merges the folder's metadata with a local cache, so a capture that went to Downloads still appears — it is just not in your project folder.
5. The MP4 I recorded is a WebM
Your Chrome build cannot encode MP4. Lens falls back to WebM and names the file for what it actually wrote, rather than giving you an .mp4 that is not one. The Settings page says which format your browser will produce. Updating Chrome usually resolves it.
6. Nothing happened when I pressed the shortcut
See Keyboard shortcuts — the usual causes are a restricted page, a conflicting binding, or a page that has not finished loading.
7. Still stuck
Open a support ticket and include what you were capturing, which browser version you are on, and what the toast or tooltip said. No account is needed.