Toad 12.9.0.71 (but saw this problem before as well).
- Start query (F9) in editor (no selection at all, sql determined with ";"
- while SQL is running (sometimes saw that even SQL finished), I click on the plan button
- Somehow toad select first word and report an error
- from that moment whenever I try to get plan-error is the same
- then I edited the query and put all in one line and "Explain plan" works again
but couldn't reproduce this bug all the time.
Brg
Damir