warning mesage in red Rated 4 out of 5 stars

Hi, I briefly see a lot of text in red beginning the word " Warning " , then this goes off before other data becomes available, what does the warning say please, its only on for a split second. Many Thanks Si.

This review is for a previous version of the add-on (1.40). 

Warning message

If you start up the extension via Tools > Exif Viewer, you will see:

WARNING!!! This extension directly accesses information on your hard drive. If this is a problem for you, you can either view the source to confirm that it is just reading the Exif data contained in the selected image, or you can uninstall the extension.\r\n\r\nNote: Not all JPEG images contain Exif data. In particular, many image editing/manipulation software don’t preserve this data, even for minor changes to the image. This may explain why Exif Viewer reports “Unable to extract all the Exif data” for many local and remote files. In some cases, you may be able to set a “Preserve Exif Data” configuration setting/option in your software.\r\n\r\nNote: Personal or corporate firewall settings may prevent the Exif Viewer from accessing remote URLs, resulting in the extension appearing to be frozen. Please ensure that Firefox has been given permission to access the internet before attempting to view the Exif data for a remote JPEG.