Layer Limit?

Is there a limit to how many layers we can have in a layout?

I currently have four layers and am unable to add any more as the little plus icon to add more is greyed out..

That's odd. I am or was using 12 layers.

Edit:

I just clicked the button like 60 times. I don't think there is a limit.

I have not purchased my licence yet, maybe that maked a difference? Also running the Beta R161 release.

The free version limits you to 4 layers. You can compare the versions here

https://www.scirra.com/store/construct-2

Thanks