Start Method doesn't start the VI

[Jim_Marihew]

I am troubleshooting a project.  One of the VIs is supposed to start a CAN listener.  It has several invoke nodes using the Ctrl Val.set method that give no errors.  Then it has a Run VI method that gives the error below. I have the VI that it is trying to start open with highlight execution on, and it doesn't even try to run.  What could cause this behavior?  Also a strange error number.

Jim

[SlippinJimmy85]

Hello Jim,

as you already stated, the error code is strange. 

What does generate the error? The called VI or the RUN VI invoke node?

Please note that if the called VI is reentrant or shared, you may not watching the actual execution flow.

A suggestion: use breakpoints to precisely figure out where the error is generated (instead of Highlight execution). As starting point, place a brakepoint inside the caller VI, then run execution. 

[Jim_Marihew]

Hi SJ, thanks for the reply.  Yes, the called VI is reentrant, but I am just running the calling VI, and all it has is the 5 invoke nodes.  I do have a breakpoint immediately before the Run VI method.  I also have a probe on the error out of that node and it does not have an error.  The image below is the start of the called VI, and the probes still say not executed when the error dialog appears.

[Jim_Marihew · Accepted solution]

Looks like this is a non issue.  I have rarely used reentrant VIs, and have never had to troubleshoot one.  The clone +ran, but did not open a panel.  The open one was not the one that ran, so my probes had nothing to see.  When I went to set a breakpoint in the VI, the menu read "Set Breakpoint (This VI and all clones)".  That was the key.  When the breakpoint executed, the clone block diagram appeared, and then I could highlight execution to see what was happening.  Not sure about the funky error message, but the issue is lack of CAN messages.

[SlippinJimmy85]

This is exactly what I meant when I suggested you to use breakpoints and be aware of reentrancy.

Good.