The file /app/code/local/GoMage/[extension]/Helper/Data.php is encoded because it is responsible for the extensions activation. This is done in order to protect our extensions. Some hosting providers may not allow encoded files on the server or consider them as malware. In such cases, this file may get suspended or even removed from the server. Missing Data.php file will cause errors in your admin panel.
If you see any errors referring to /app/code/local/GoMage/[extension]/Helper/Data.php file, you should first of all verify whether this file exists on the server. Even if it exists, it may have been corrupted as a result of a decoding attempt. You should copy the original file from the extension package and re-upload it to the server. Secondly, you should contact your hosting provider and inform them that this file should not be removed or suspended by antivirus because the extension will not work without it. Your hosting provider must add this file to the exception rules of the server antivirus in order to prevent further errors or warning messages.