Greetings.

Recently Waterfox Mobile is randomly and frequently crashing. It crashed twice while I was writing this post. Sometimes it crashed when I am opening a new tab, other times while I am scrolling down, and some times I even while I am just reading or typing.

I can't pinpoint exactly when it started, but I have not changed anything about it's installation or my phone, other than the app updates.

I've been using Waterfox for some time now and today I realized I was getting micro-flashed by a white screen that launched shortly before rendering my new tab page (for which I have an extension to replace).

In case you haven't realized, you too might be getting flashed. In case you want to fix this here is what I did:

1. Go to about:support on your address bar.
   
2. Open your profile folder
   
3. Look for a folder called chrome. If it doesn't exist, create it
   
4. Create inside of it "userChrome.css" and "userContent.css", make sure their extension is .css and not .txt
   
5. Copy and paste the following into userChrome.css:

/* Target only the tab panels container during rendering transitions */
.tabbrowser-tabbox,
tabbrowser tabpanels,
#appcontent {
  background-color: #1c1b22 !important;
}

/* Specifically target the blank frame while an extension loads */
browser[type="content-primary"]:not([src]),
browser[type="content"]:not([src]) {
  background-color: #1c1b22 !important;
}/* Target only the tab panels container during rendering transitions */
.tabbrowser-tabbox,
tabbrowser tabpanels,
#appcontent {
  background-color: #1c1b22 !important;
}

/* Specifically target the blank frame while an extension loads */
browser[type="content-primary"]:not([src]),
browser[type="content"]:not([src]) {
  background-color: #1c1b22 !important;
}

1. Copy and paste the following into userContent.css:

/* Target only internal blank pages and your custom new tab extension */
@-moz-document url(about:blank), url(about:newtab), url(about:home), url-prefix("moz-extension://") {
html, body, #newtab-customize-overlay, :root {
background-color: #1c1b22 !important;
background: #1c1b22 !important;
}
}

1. Save both .css' - Go back to about:support and click "Clear Startup Cache". This won't delete your actual cache, just your app behavior cache.

That is it! Hopefully someone finds this useful.