Using new computer and Firefox settings synced from previous computer. Two major issues started when using the new computer: When opening links in new tab (manually by right-click link and chose option to open in new Tab) nothing happens. The URL appears in the tab address line but the web page doesn't load. Pressing enter doesn't fix it. Copying URL and opening new tab, and pasting URL, doesn't load the page either. This can occur when first open Firefox, or can be after some time. The other issue is Gmail often showing "Not connected." and retrying. The computer is connected to the internet, and can access web pages in other windows in Firefox, or in Chrome. Google apps, such as Keep, also exhibit unable to connect to Google. Have to close Firefox to fix this and can often return shortly after signing into Gmail again. Have tried disabling extensions and add-ons, resetting preferences and tab settings, clearing temp files and cookies, resetting Firefox, uninstalling Firefox and re-installing. All to no avail. The previous computer doesn't have these issues.