Inventor Nastran has a longstanding defect in which result probes become permanently displayed but are no longer recognized as active probe objects.
After placing a probe on a result plot, such as von Mises stress, the following can occur:
The probe cannot be selected or moved.
The Delete Probes command is greyed out.
Turning off Object Visibility → Probes has no effect.
The probe label remains displayed on the plot.
Additional probes may become unusable.
The available workaround is to finish the Inventor Nastran environment, re-enter it, and reload the results. This is highly disruptive, particularly for large nonlinear or explicit analyses whose results can take considerable time and memory to load. Reloading large results can also increase the risk of instability or a crash.
This problem was reported to Autodesk in January 2020 and continues to be reported in current versions more than six years later:
https://forums.autodesk.com/t5/inventor-nastran-forum/probes-staying-on-screen-after-quot-delete-all...
A basic post-processing tool should not require restarting the analysis environment to recover from a probe-display failure. Autodesk should permanently correct the probe-object state and graphics synchronization so that:
Every displayed probe remains recognized as an active object.
Probes can be selected and moved reliably.
Delete Probes removes every displayed probe.
Object Visibility → Probes consistently controls all probe labels.
Restarting the Nastran environment or reloading results is unnecessary.
Please confirm that this defect has been logged, provide its tracking status, and prioritize a permanent correction in an upcoming Inventor Nastran update.
