The following applies to commit: 8f89fa2

Background
The fact that this is - presumably - a Synchronization Barrier XNode issue surfaces when haphazardly (<- we'll describe what this means below) upgrading FTW in LabVIEW 2016. Either way, a hidden broken wire will appear on ~\tests\core\FTW-PerfTest-JSON-Fetch.vi which must be "selected" from the Error List and subsequently deleted. Presumably this could affect other source using this xnode and a similar fix would be required.

Observation One
Suppose you haphazardly upgrade FTW in LabVIEW 2016 by opening FTW.lvproj without first clearing the object cache and mass compiling. Then the following error occurs and curiously applies to only one of two synchronization barrier xnodes on the diagram when opening ~\tests\core\FTW-PerfTest-JSON-Fetch.vi:

Note: you'll see that I'd attempted to unwire / rewire the synchronization barrier xnode and remove unwired terminals in an attempt to force a recompile, but the error seen persisted. Furthermore, there's another instance of the synchronization barrier xnode on the diagram (not seen here; it's behind the Error List window) which has no issue (i.e. if you remove the complaining instance of the synchronization barrier xnode the VI compiles happily).

If you have the following LabVIEW.ini keys, you'll have the ability to regenerate code for the xnode, which will result in the error described below (for which there is a trivial workaround):

SuperSecretPrivateSpecialStuff=“TRUE"
XNodeWizardMode=True
LVDebugKeys=True

Observation Two
If you more carefully upgrade FTW by clearing the object cache (and then closing and reopening LabVIEW for sanity) and then mass compiling the new FTW source, you'll see the following error upon opening ~\tests\core\FTW-PerfTest-JSON-Fetch.vi:

Observation Three
The "hidden broken wire" issue recurs upon mass compiling the FTW source.

Workaround
Upon double-clicking the error shown in the list, you can simply delete the hidden wire and ~\tests\core\FTW-PerfTest-JSON-Fetch.vi will compile and run successfully.