Yes I did. I also deleted the virtual source and sinks and replaced them, as well as the blocks that were in front of/behind those virtuals, that didn't help.
So I pulled from git to get the latest code and re-installed. I'm now using gr 3.7.10, and the error persists.
Here is some more information:
1) Whenever I open grc fresh, I get those messages and the wires are disconnected automatically. I can reconnect them and run the flowgraph, and it works fine. But the next time I close and re-open grc, the error messages will be printed and the wires will be disconnected.
2) If after I've connected the message ports I make a change to any other blocks in the flowgraph, grc will automatically delete those wire connections and reprint the error messages. So this must be related to the grc checks it makes whenever something changes in the flowgraph.
Any chance someone else could try passing messages around using virtual souce/sinks? Narrow this down to a real bug or my computer.
Rich