I am not positive what is causing the issue, but here is a list of things that may fix it. I understand some look strange, but I promise I have seen them fix issues.
1.Hit ctrl-shift-Run Arrow on the Top level VI to force a recompile of the hierarchy.
2.Open up the subVI (really a sub-subVI) called Font Style.vi. On the block diagram, in the upper left-hand corner, there is a property node. Change the property node to a different property, and then back to the original "TextFont" property. Save the VI.
3.Take a look at these links
Error "-2147352573 Member not found in the xxx.vi" with NI Reports VIs in LabVIEW 6.0f/websearch/2FCAAF080951FCAB86256982007AA16C?OpenDocument�> NI Reports Doesn't Seem to Be Working Pr...4.Re-install LabVIEW
Evan