insupportable

adjective2

1. •
   That cannot be tolerated or endured.

   • My Lord you do me most insupportable vexation. — 1604
2. •
   That cannot be supported; that cannot be demonstrated or proved. (of a statement, claim, argument, etc.)

   • This is a critical error, which undermines the report and leads the advisory group to make a series of contradictory and insupportable recommendations. — 2012