The most recent patch brought us a complete balance overhaul for Super Heavy Fighters, and under their new balance these ships can no longer use CAU5 or above (for more detail see balance notes).
If you had a CAU mounted on your SHFs, no need to worry, the change is implemented in a way that doesn't lead to character corruption. Once you log in, your ship and loadout will be the same as before but the game will not let you undock until you unmount the armor. Since people who had invested in heavier armors for their SHFs before this patch had no way of predicting this change:
Special Equipment Dealership in Connecticut is buying back Capital Armor Upgrade 4, 5, 6 & 7s at full price. (When logging in, immediately access Connecticut using /conn command, unmount armor, undock from New Haven, sell armor at Special Equipment Dealership, and use /return command while on New Haven to return to your previous base.)
The refund will only be available for a limited time. There will be another notice posted in this thread one week in advance.
Refund will be wrapped up on July 12th
Special dealer will no longer accept cap armors after next Monday's daily restart.
So if you've been trying out some armors and wanted to scrap em by the end of the refund, now would be a good time to do it.