I am part of an LLC that showed a income loss in box L of the K1. Why can't I get that loss added to my income as I was able to do last year.

[M-MTax]

That's your CAPITAL ACCOUNT which measures your investment of equity in the partnership. You CAN'T take a loss based on the figures in Box L of your K-1 while you're holding an interest in the partnership.

[JeffreyR77]

Your equity in the partnership determines whether you can deduct losses from your income. 

As @M-MTax said if Box L of your Form K1 shows your Capital account balance i.e. your equity in the partnership. 

If you have a $0 or less balance in your Capital account at year end, you are not allowed to deduct a loss as you no longer have any equity in the partnership.  You in essence no longer have any at risk investment to write off.

Form K1 (1065)