"Unanticipated circumstances" refers to unexpected events or situations that were not foreseen or planned for. It means things that happen unexpectedly, catching people off guard, and causing potential changes in plans or outcomes. Full definition
We understand that plans occasionally change and unanticipated circumstances sometimes arise. (prairieyoga.org)
Brewery Gulch Inn STRONGLY advises guests to secure trip cancellation insurance to protect themselves against Acts of God or any other unanticipated circumstances. (brewerygulchinn.com)
That's a much weaker quality requirement than is necessary for generalized commercial software which is expected to work correctly under a wide range of unanticipated circumstances. (realclimate.org)