Calculate Depreciation

HI Everyone,

I have got an issue with the depreciation and wanted to ask you how to go about it. I've got an asset which I have partially acquired in 2015, with further acquisitions done in 2016. I tried to run the Calc. Depreciation for 2015, however it won't let me, for the simple reason that other transactions exists post my depreciation date which is set as at 31 December 2015.

What's the way forward?

Thanks in advance