It's time to pay the rent to the tenant but there's no interaction to do it in the mailbox.
Edit By Crinrict: Adjusted Title fit bug report at AHQ
Ideas
For me it is when I load a game as tenant where I am on my home lot then the rent is 0. Then when travel away and come back a rent is shown, but when I do it for example on Tuesdays, the amount of the rent for monday is missing. Like the rent calculation is not startet on game load and not stored or whatever.
