Thank you very much!
I've switched off "Wiktionary" (actually I've done it before - I think, this option is switching on automatically). Now I can't reproduce the error.
If it appears again, I'll try to prepare a test scenario with less copmlex logic.
(After this error, I think, some variables weren't saved - and the following bot's answers were incorrect because of missing right values of variables like "topic".)
Now AIM