I had this problem today and thought I would share the solution I found since it took me more than 5 minutes to find it.
I was trying to load an example from within the NI Example Finder and kept getting the error "An error occurred – The NI HelpServer could not be found". As it turns out there is a simple solution involving launching a VI to fix this.
In order to ensure credit where it is due, though, I am going to place the link I found in the LabVIEW community first and then the link with the solution. Please click the first link and give credit to the poster if it fixed your problem, too!
First link - > (see post #2) https://forums.ni.com/t5/LabVIEW/Troubles-with-examples-opening/td-p/281122
Second link -> https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019OZlSAM&l=en-US