What does thios error mean

[Stephen P. Smith]

When a friend is running an older version of GDB, he is getting this error message:
  Error: text doesn't contain any characters tagged with "_show_variable"

What is the usual cause of this?

sps

--------------- The Stack trace --------------
text doesn't contain any characters tagged with "_show_variable"
    while executing
"$W bbox $tag.first"
    ("Text" arm line 2)
    invoked from within
"switch -- [winfo class $W] {
	Menu {
	  # Recognize but do nothing.
	}

	Text {
	  lassign [$W bbox $tag.first] x y width height
	  set left [expr {[w..."
    (object "::.srcwin0.__balloon" method "::Balloon::showballoon" body line 22)
    invoked from within
"::.srcwin0.__balloon showballoon
.srcwin0.srcwin.container.pane2.childsite.con.p.pane2.childsite.st.lf.childsite.clipper.text _show_variable"
    ("after" script)errorCode is NONE