I stumbled on the solution: To fix, right click on the PS2000 Open VI, then click “Relink to SubVI”

Can't run PicoScope2000aExampleRapidBlock.vi [PicoSDK_32_10.6.10.22] ... LabView 2015SP1 complains about connection to PicoScope2000aOpen.vi ... But PicoScope2000aExampleAWG.vi also calls PicoScope2000aOpen.vi with the same connections … and runs fine! [target is 2206A] ... what's the difference???

In the latest SDK download, "PicoScope2000aExampleBlock" is exact same as "PicoScope2000aExampleAWG" ... the 'real' "PicoScope2000aExampleBlock" seems to be missing from the PicoSDK_32_10.6.10.22 download.