If I understand correctly and you are using Draw GUI, have you followed the instructions related to that from the manual?
The manual is a note included in the asset, but you can also see it online. See the section “Using Draw GUI”.
And if you are using Draw GUI, you don’t need to get the camera positions, so changing these to something else will probably fix it.
However, if you are not using Draw GUI, then this might be a bug, but I’m not completely sure, I will have to investigate more.
Let me know if this helps, and if you still have problems, a screenshot would help.