Is that site a registered site?

You may have corrupt sessionstore [v56] sessionstore.jsonlz4 file(s). Delete all sessionstore* files and the sessionstore-backups folder.

Type about:support<enter> in the address bar.

Under the page logo on the left side, you will see Application Basics. Under this find Profile Folder. To its right press the button Show Folder. This will open your file browser to the current Firefox profile. Now Close Firefox.

Linux: Under the page logo on the left side, you will see Application Basics. Under this find Profile Directory. To its right press the button Open Directory.

Locate the above file. Then rename or delete it. Restart Firefox.

Don't delete the files if you need to rescue any data from them, just move them out of the profile folder to some location where Firefox doesn't look for them. You can try to read out their contents using this tool: https://www.jeffersonscher.com/res/scrounger.html

In the address bar, type about:crashes<enter>. Note: If any reports do not have BP- in front of the numbers/letters, click it to submit them.

The crash report is several pages of data. We need the report numbers to see the whole report.

Using your mouse, mark the most recent 7 - 10 crash reports, and copy them. Now go to the reply box and paste them in.

For more help on crash reports, see; https://support.mozilla.org/en-US/kb/firefox-crashes-asking-support

When I typed About:crashes I got the following message No crash reports have been submitted. Also no sessionstore files existed in the main directory. I had quite a few backups which I deleted but the main profile folder seemed empty of any sessionstore files.

I called for more help.

The sessionstore files are created when Firefox closes.

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

After running in safe mode the problem didn't appear to be happening ,but after doing a system restart the problem promptly came back. Also it took the liberty of deleting my history of my previous session but this time I do have a crash report as follows: https://crash-stats.mozilla.com/report/index/bp-ce41ccca-f13e-466c-9136-db9740181102 This only seems to happen when firefox is loaded for the first time and I attempt to either restore my previous session or load previously saved bookmarks after that it sees to work fine.

bp-ce41ccca-f13e-466c-9136-db9740181102 Signature: msmpeg2vdec.dll@0x25a3fb

tmmon64.dll = Trend Micro UMH Monitor Engine

TmUmEvt64.dll = Trend Micro Eyes

msmpeg2vdec.dll = Microsoft DTV-DVD Video Decoder

This is for Sumo's Related Bugs 1490637 NEW --- Crash in msmpeg2vdec.dll@0x25a3fb correlated to Trend Micro

1180561 RESOLVED FIXED startup crash in [@ msmpeg2vdec.dll@0x25a3fb ]

Go to the Trend Micro website and download the full installer for the programs you have. +++++++++++++++++++ See if there are updates for your graphics drivers https://support.mozilla.org/en-US/kb/upgrade-graphics-drivers-use-hardware-acceleration

It's definitely something to do with Trend Micro as I rebooted in selective startup mode with the Trend Micro Solution Platform and the Platinum Host service disabled and it worked fine but seeing I only updated it to the most recent version a few days ago I don't think I can update it any further. Also I have the most recent Nvidia graphics driver. That crash log was only generated after I tied to restore one of the crashed tabs and Firefox promptly crashed which doesn't usually happen.

Contact Trend Micro support.

I've done that but should I file a bug report with Mozilla as well? After all the more people working on the problem the better from my point of view.

If the problem is with Trend Micro, there would be not much Mozilla could do about it.

Wait for Trend Micro to respond.