It sounds like one of three things may have happened:
(1) You replaced your gallery's 'svcore' folder with the SimpleViewer-Standard 'svcore' folder rather than the SimpleViewer-Pro 'svcore' folder.
(2) You used the SimpleViewer-Pro 'svcore' folder but your gallery's 'svcore' folder was not overwritten.
(3) The upgrade was successful but you are viewing an older version of your gallery cached by your browser.
Solutions would be to:
(1) Ensure that you are using the SimpleViewer-Pro 'svcore' folder from the SimpleViewer-Pro download zip package ('simpleviewer_pro_231/web/svcore/').
(2) If you are unsure as to whether or not your gallery's 'svcore' folder is being overwritten, try deleting it from your web server first before uploading the SimpleViewer-Pro 'svcore' folder in its place.
(3) After replacing the 'svcore' folder, clear your browser's cache before reloading your gallery's web page to ensure that your browser is fetching and using the most recent gallery files from your web server.
SimpleViewer Support Team.