Today I modified a strict typedef (added two controls). A couple of my VIs that use the typedef were then expectedly broken. I fixed those but noticed there were still errors being reported. I went to the top of the error list and found a handful of entries with the "red X", but without any details on what the problem was...just: "...this VI is not executable....", one example that had a broken arrow: an accessor that writes an enqueuer object to private data. I hunted around and could find no "real" problem with any of the reported VIs, e.g., no broken wires. So I did a "Save All (this project)", then mass compiled...got a bunch of "bad VIs" almost all AF VIs, then exited LabVIEW.
Brought LabVIEW back up and opened my project and WAHLAH!, all is well???
If it happens again, I'll capture the errors for the forum. For the time being, I guess my SOP will be to "Save All", Exit....restart LabVIEW whenever anything looks out of kilter.
