The "bigfile.000.tiger" error is one of the most notorious technical hurdles encountered by players of the Tomb Raider
The .bigfile format in the Foundation Engine (used for Rise and Shadow of the Tomb Raider) is a container for compressed assets. Each bigfile has a header containing:
C:\Program Files (x86)\Steam\steamapps\common\Tomb Raider
bigfile000.tiger and delete it (or move it to a backup folder).bigfile000.tiger is missing and download a fresh copy (approx. 5-8 GB).While unconfirmed, fans speculate the name is either an internal code name or a play on "TIGER" as an acronym for "Tomb IGame Engine Resource." Regardless, when you see this error, the game is telling you that it cannot read or trust the primary asset archive.