hi, this crash is caused by a library named sboxdll.dll which seems to be part of an enterprise sandboxing solution (Invincea Sandbox/Dell Protected Workspace). if your pc is part of a managed enterprise environment, please get in contact with your it department about that matter...

Thanks for the rapid reply. It's a personal PC, bought from Dell but with Dell Protected Workspace pre-installed. Firefox worked till I tried to change the Adobe add-on settings this morning - can I just delete that file somewhere to get me back to how things were? There doesn't seem to be an easy way of removing Dell Protected Workspace... but, as I say, that is not the main problem as it has worked OK for several months until this morning.

please try tweaking the programs settings then and exempt firefox and/or adobe from any form of sandboxing if it is not possible to install the program altogether...

You can try to open the prefs.js file in the Firefox profile folder in a text editor and look for a plugin.state line that refers to this plugin or set them all to 0 (never activate).

• plugin.state (0:Never Activate; 1:Ask to Activate; 2:Always Activate)

You can find the profile folder in this location:

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

• http://kb.mozillazine.org/Profile_folder_-_Firefox

"AppData" (XP: Application Data; Mac: ~/Library; Linux: ~/.mozilla) is a hidden folder.

• http://kb.mozillazine.org/Show_hidden_files_and_folders

Thanks for these helpful suggestions. I decided to remove Dell Protected Workspace completely as I don't need it - and now I can open Firefox again without difficulty.