Recently, I was trying to process the out of the box Production order cube available in AX 2012 R2 and got the below error:

The conversion of nvarchar data type to a datetime data type resulted in an out of range value.

I was getting this error due to the DaysDelayed column in ProdTableExpanded View in AX. I found this when I run the following select statement in SQL server management studio:

select DaysDelayed from ProdTableExpanded;

After running the above query, I got the same conversion error which I mentioned above. The resolution is to install the hotfix KB2859489. Here is the lifecycle services link from where you can download and install the hotfix:

After applying the hotfix code in ProdTableExpanded view, the cube successfully processed and deployed in SSAS database.