After Override same amount as cost leads to Depreciation Request ending in error

Hi,

Depreciation Request ending in error and log file shows the error as

“Error: Depreciation cannot exceed depreciation limit.

Cause: Override amount is too large.

Action: Enter an override amount that will not cause depreciation to exceed the depreciation limit.

Asset ID ****** (******) -> ** FAILED **”

The asset is added in the current open period with the following details and user tried to override the amount same as cost

Asset cost= 500000.00

Dep Method=STL

Rate=33.33%

Units=75

DPIS= 15-DEC-2014

Current Open Period=Aug-15

depreciation Override amount  inserted by user =500000

User needs to fully depreciate the asset in the period added

What could be the reason for this?