To enable DOM storage and cookies in Firefox:
- Type the following in the subject line: about:config.
- Locate the dom.storage.enabled option. The value should be set to True. If it is set to False, right-click the dom.storage.enabled option and select Toggle.
- From the Firefox options menu, select the Options icon.
- Select the privacy option on the left side of the screen.
- From the drop-down list in the History section, select the Use custom settings for history option.
- Ensure that the Accept cookies from sites option is selected.