The two crash report shows two things one for crash in .js file and another in Assertion failure caused by Adblock plus addon.

Try to remove the conflict addon and then start firefox and see whether it again happens. using a stable version is one that can keep away from this type of error.

The diversity of these crash signatures makes it challenging.

The most recent report had 93 user comments during the past week. Two of them linked it with the HTTPS Everywhere extension. The entry in the bug tracking system makes the same connection. I suggestion disabling that one.

In fact, try disabling all extensions you can live without for 48 hours. Open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Extensions.

Usually a link will appear above at least one disabled extension to restart Firefox. You can complete your work on the tab and click one of the links as the last step.

The other 3 most recent crash reports (that show as links in your question) are low incidence, so there isn't as much data available.