Toad 184.108.40.206 (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.
Bug is present on 11 and 12 databases so I think it is something related to "internal" Toad parsing and manipulating with SQL text.