Describe the bug
Nullpointer exception when placing button on microblocks

To Reproduce
Steps to reproduce the behavior:

1. Place illuminated button on multipart block

Expected behavior
Nothing like with the vanilla button.

Crash Log
crash-2021-04-29_18.55.08-client.txt

Versions
Checkout at bc91f0c

Screenshots/Videos

Are Illumar Buttons still disabled in the 1.16 release? I see their recipe on the wiki but not in-game on Illumination 4.12.0.

Placement logic around multipart buttons has been re-written in CBMultipart (TheCBProject/CBMultipart@ee4de53)

As for Illuminated buttons, they are not in atm. If/when they return, this issue won't apply anymore

I think this may have been fixed on CBMultipart side. Using the latest commit from 1.15 branch and I can place the button on a Microblock cover just fine. What version of CBM are you running?

Btw, illumar buttons are not fully implemented yet. Still missing textures, etc.

The client seems to crash when placing an illuminated button on a cover with solid block behind the cover. The screenshot shows all not crashing variants with green lamps. If someone tries to place the button on the cover behind the red lamp, the client is crashing. I think the button thinks it should be placed on the solid block, but it cannot because there is a cover before the solid block and thus crashing the client. Note that the second cover is not at the same position as the first cover.

Forgot to comment, but this seems to be fixed in 1.16 version of CB Multipart. Will know more later today once I'm finished porting.