Mark Net->"select via layers" empty??

[vtcad]

Because of my .tf I have to open the Option Menu in the Mark Net util-

SelectViaLayers, and deselect some layers. I find that once and a
while when I revisit this form, all my layers disappear, causing me to

restart Cadence,or manual add them back to the "select via layers"
choices. Anyone else expieriencing this or know why it happens?

thanks