Speculation is that their cash flow have been adversely effected by the situation in Venezuela.
A news item in Spanish related to the shutdown,
Tiara Air N.V., operating as Tiara Air Aruba, is (was) an airline headquartered and based on the grounds of Aruba, in the Dutch Caribbean, which began operations in 2006
Thanks to Robert L for the information.
Photo © Jehan M. Ghouse
Photo © Roger Cannegieter - Curacao Aviation Photography