Arma: Data File too short/Arma OA No Entry and Data File too short

[SpennyG98 1]

Whenever I try to launch Arma 2 I get a

Data File too short 'addons/anims.pbo'. Expected 650211804 B, got 446300160 B

When I try to launch Arma OA I get a

No Entry 'bin/config.bin/CfgInGameUI/MPTable.shadow'.

followed by a

Data File too short 'c:/program files

(86x)/steam/steamapps/common/arma2/addons/anims.pbo'.

Expected 650211804 B, got 446300160 B

[ProfTournesol 956]

Look at this topic and follow the advice.