Why is the path correct?
Still:
SearchEverything: Getting Opus to work with Everything v4.0 SearchEverything v.4.0.0.0.rar
It is better to add this to your code, then it will always open in a new tab.
<instruction>Go NEWTAB</instruction>
it will turn out like this
<instruction>Go NEWTAB</instruction>
<instruction>C:\Program Files\Everything\SearchEverything.exe "{dlgstring}"</instruction>
