User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Firefox/58.0 Build ID: 20171024124937 Steps to reproduce: 1- Just open browser 2. See in the browser console many errors: getScreenshot error: Unix error 2 during operation open on file /home/wellington/.cache/.mozilla/firefox-trunk/v3uent20.23Set2017/thumbnails/d9e13e879d66f1241665c3b3ba6fbb67.png (Arquivo ou diretório não encontrado) getScreenshot error: Unix error 2 during operation open on file /home/wellington/.cache/.mozilla/firefox-trunk/v3uent20.23Set2017/thumbnails/aae1cf3cb358fab3f0685775655dc000.png (Arquivo ou diretório não encontrado) Screenshots.jsm:61 getScreenshotForURL resource://activity-stream/lib/Screenshots.jsm:61:7 throw view-source:resource://activity-stream/lib/Screenshots.jsm Actual results: errors from view-source:resource://activity-stream/lib/Screenshots.jsm like: getScreenshot error: Unix error 2 during operation open on file /home/wellington/.cache/.mozilla/firefox-trunk/v3uent20.23Set2017/thumbnails/d9e13e879d66f1241665c3b3ba6fbb67.png (Arquivo ou diretório não encontrado) Expected results: No errors. Thanks

I’ve managed to reproduce this bug when trying to open a profile created on a different machine. As seen from the errors the location of the cache is not in the Firefox profile.

Is it possible that "browser.pagethumbnails.capturing_disabled" is enabled and set to true? That's the only way I got it to reproduce. Also did you happen to move that profile? Or delete /home/wellington/.cache/.mozilla? As I assumed in my previous comment.

(In reply to Andrei Oprea [:andreio] from comment #2) > Is it possible that "browser.pagethumbnails.capturing_disabled" is enabled > and set to true? That's the only way I got it to reproduce. > Also did you happen to move that profile? Or delete > /home/wellington/.cache/.mozilla? As I assumed in my previous comment. Hi, I'm checked and "browser.pagethumbnails.capturing_disabled" is true. But I don't change this setting manually. About the profile I don't moved or changed the location, but alert on the console is frequently about profile permissions and access problem.

"browser.pagethumbnails.capturing_disabled" should not be used. It was most likely set by an addon. What you should do is right click the pref in about:config and select "Reset". After doing this you should no longer be seeing the errors.

Please re-open if the solution above did not fix it.

Bug 1421902 is for FaviconFeed and might be triggering around the same time as this getScreenshot message during tests.

The fix probably shouldn't just check the "capturing_disabled" pref but more of either avoiding the exception with smarter control flow or not being noisy for this exception.