We are a Trust, have received BI from our loss in the Maui Fire., lost a retail shopping center.  The income will be reported on a K-1 to the trustees, however the K-1 will not let me report Ordinary Business income and rental real estate income on 1 K-1, it says I must issue 2 K-1's, not allowed values on more than 1 line on the K-1 from lines 6-8, why not?  Why can you not have ordinary income and real estate income as that is how I am supposed to report it.  

Separate K-1s are used to facilitate the IRS requirement to attach activity reports for each type of income. 

Per the Instructions for Form 1041 Schedule K-1 Boxes 6-8: "The fiduciary will provide you with a separate schedule showing your distributive share of income from each trade or business, net rental real estate, or other rental activity."

As long as you inform the trustees that both K-1s are to be included on their tax returns, there should be no effect on their tax situation.