Chaos terminators bug
 

Currently, as many Chaos Terminators as you want can replace their twin-linked bolters with either a heavy flamer or a reaper autocannon. However, page 94 of Codex: Chaos Space Marines states that only model in the unit may replace their twin-linked bolter with one of those two guns. If the unit is at full strength (10 models) then it could take two.

Nevermind, just a weird way to have the unit setup.

:) There is no reason to nevermind. This is a bug. There should be an validation error if you select more than one of these weapons, or if there are 10 then 2. Please visit our website www.ab40k.org. I have posted a bug report for your find! We will have it fixed really soon!