I don't know why the developer is having so many issues with the script now however to solve the problem (I hope you understand this in English) do the following:
Open the Messenger Plus! Preferences > Click Scripts > Highlight IPGet and click Edit > Select IPGet_menu.js from the Drop Down Insert the following line at the beginning of the code:
js code:
var fileInterface = MsgPlus.ScriptFilesPath+'\\IPGet_interface.xml';
Cheers
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