Seems I do not need to post all 82 statements as while preparing them and carefully reading one after one I found 2 indexes (same DB and table- probably same creator) with names like :
"ind1 (Non-Unique, Non-Clustered)" and "ind2 (Non-Unique, Non-Clustered)".
My bad- I did not find them till today.
As I found they were ReBuilt/ReOrganized every week- therefore SP failed every week run
(as these 2 indexes somewhere in the middle of total index list looks like sql failed on them keeping in mind error, proceeded with other indexes but at the very end returned this error)
Anyhow I renamed these 2 indexes (removing "(Non-Unique, Non-Clustered)" from name) and hope next run everything should be fine
Thanks everybody for help (as always)