Mozilla Monitor website will be down for 2 hours starting 5/20/2025 at 6 AM PT. Visit our status site for updates.

Avatar for Username

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was archived. Please ask a new question if you need help.

Responsive Design Mode says "no list available", how do I fix this?

  • 5 replies
  • 18 have this problem
  • 19 views
  • Last reply by joshsharp

joshsharp
joshsharp

Hey folks,

I've been using the new Responsive Design Mode for a while, it's very handy. But recently it's stopped showing any device presets (see image). I can't click on the dropdown nor add a new preset.

Things that could be related:

1) I have multiprocess turned on. 2) I recently installed Nightly (alongside regular Firefox) which might have broken the config? 3) I tried adding the `devtools.responsiveUI.presets` config value but I still have no list.

Thanks in advance.

Hey folks, I've been using the new Responsive Design Mode for a while, it's very handy. But recently it's stopped showing any device presets (see image). I can't click on the dropdown nor add a new preset. Things that could be related: 1) I have multiprocess turned on. 2) I recently installed Nightly (alongside regular Firefox) which might have broken the config? 3) I tried adding the `devtools.responsiveUI.presets` config value but I still have no list. Thanks in advance.

Chosen solution

Aha! I've been upgraded to Firefox 55.0.3 now and the list has been restored. Who knows what happened there, but I suspect corruption from installing Nightly.

Read this answer in context 👍 1

All Replies (5)

joshsharp
joshsharp Question owner

For some reason the image didn't attach, here it is.

joshsharp
joshsharp Question owner

Anyone?

cor-el
cor-el
  • Moderator

Firefox would normally retrieve this list via internet as set via devtools.devices.url.

So make sure that you aren't blocking this request.

This could also be a problem with IndexedDB.

Current Firefox releases with multi-process enabled store device data (Add Device) in an IndexedDB SQLite database file in the object_data table as BLOB data.

You can check the storage folder in the profile folder

  • storage -> permanent
    indexeddb+++fx-devtools/idb/478967115deegvatroootlss--cans.sqlite
joshsharp
joshsharp Question owner

Thanks very much for this! I don't think I'm blocking that request as I can load it fine in the browser. I think the issue might be the sqlite DB, as if I attempt to connect to it with sqlite3 in Python I get:

SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

But perhaps I am misunderstanding and trying to do the wrong thing, the fact that there's an issue with the first few bytes suggests the format is something different entirely. I'm not very familiar with sqlite.

Is this DB something I can delete so it can be generated again, or do you have other ideas?

joshsharp
joshsharp Question owner

Chosen Solution

Aha! I've been upgraded to Firefox 55.0.3 now and the list has been restored. Who knows what happened there, but I suspect corruption from installing Nightly.