Privacy, Data & Troubleshooting

Troubleshoot common issues

Most surprises in DevTools+ by URLflows come from pages Chrome keeps extensions out of, or from limits Chrome puts on what an extension can do. Here's how to tell which, and what to do.

The page tools are missing or do nothing

You're on a page Chrome keeps off limits. Extensions can't run on Chrome's own pages (chrome:// addresses, the New Tab page), the Chrome Web Store, or other extensions' pages. The toolbar panel says Page tools can't run on this page there; the tools that don't need the page, like Color picker, Request rules, Encode and decode, and Extensions, still work.
It's a file on your computer. For file:// pages, open chrome://extensions, choose Details on DevTools+ and switch on Allow access to file URLs.
The tab was open before an install or update. DevTools+ starts itself on tabs that were already open, but if a tool still doesn't respond, reload the tab.
The tool is switched off. Check Settings → Tools → Toolbar panel.

Chrome says the browser is being debugged

Chrome shows its "debugging this browser" bar while Emulate, Console errors, Record a HAR file or an Element grab of something taller than the window is running. Chrome draws that bar itself and an extension can't hide it. It goes away when the tool lets go:

Console errors records for 6 seconds, then lets go.
Record a HAR file lets go when you press Stop and save or Cancel recording.
Emulate lets go when everything is back to "as is", or when you close the tab. The toolbar icon shows EMU until then.

Closing the bar yourself (its Cancel button) stops whatever was using the debugger. A HAR recording stopped that way isn't saved, so start it again.

"Another debugger is attached to this tab"

DevTools+ says this when something else already holds the debugger on that tab, such as another extension or DevTools opened for an extension. Close it, or switch the other extension off from the Extensions tool, and try again. On Chrome's own pages and the Web Store you'll see that Chrome doesn't let extensions debug the page instead; there's no way around that one.

A request rule doesn't apply

Reload the page. A rule applies to requests made after it's on, so what already loaded doesn't change.
Check that it's on. The badge on the toolbar icon counts the rules Chrome accepted. A rule with a problem, or one Chrome refused, is left out, and its card in Settings → Request Rules says why.
Check where it matches. The URL filter, Sites, Requests made by and Kinds of request all have to fit. An empty filter matches every URL, and no kinds picked means every kind, the page itself included.
Two rules disagree. Rules lower in the list win.
The page sets it another way. Turn off Content Security Policy removes the CSP headers; a policy written into the page's own HTML isn't a header, so it stays. Allow CORS adds the response headers, but a preflight that fails on the server still fails.
Another extension changes requests too. An ad blocker or privacy extension can block or change the same request. Switch it off from the Extensions tool to rule it out.

A grab won't paste

When the page can't reach the clipboard, the grab is saved as a file instead: look in your Downloads folder. Also check Settings → Tools → Screen grabs: if After a grab is set to Save a file, nothing is copied.

Record the tab asks which tab to record

Chrome hands a tab's video straight to an extension only after you click the toolbar icon in that tab. In the pop-out window, Chrome's share window asks which tab to record instead. Keep the pop-out open until you stop, because closing it ends the recording.

The right-click items do nothing

On an element inside an embedded frame, DevTools+ says the right-click tools work on the main page only.
If it asks you to right-click the element again, the page changed after your click. Right-click it once more and choose again.
If the items are missing, check Show the tools in the right-click menu in Settings → Tools.

A change didn't last

Outline every element, Layout grid, Edit page text, Turn off CSS and Mask PII last until you switch them off or the page reloads. A setting changed with Site switches needs a reload to apply. Hidden elements and container zoom are the ones that come back on every visit.

The DevTools+ tab isn't in the Elements panel

Close DevTools and open it again. DevTools only adds an extension's tab when it opens. If the tab row beside Styles is narrow, look under the » overflow.

A shortcut doesn't work

Chrome sets shortcuts, and leaves one unset if another extension already uses those keys. See them in Settings → Tools → Keyboard shortcuts, and press Change shortcuts to pick other keys.

Still stuck?

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