[0.15.15] Switching tabs in constant combinator causes crash

[nyanlyar]

What I did:
Loaded the game, placed new constant combinator right after that. Clicked in its GUI to add a new signal. Then tried to switch to the "Signals" tab.

What happened:
Game crashed.

What was supposed to happen:
Game will switch the tab and won't crash.

How to reproduce the crash:
Load the 60.zip game save from the attached archive. Place new constant combinator, and click in its GUI to add a new signal. Switch tabs in the signal adding menu. It might not happen the first time you do it – opening and closing the GUI (constant combinator's, not signal adding menu) several times and trying to switch tabs in signal adding menu after that was enough for me to cause the crash about 10-15 times.

Additional info:
The bug seems not to occur with arithmetic and decider combinators, already placed constant combinators and assembling machines (only tier 1 assembling machine was tested).
The bug is (seemingly) not related to the "Signals" tab, the crash might happen when switching to another tab.
There is two crash logs in the attached archive. They are a little different, yet both are related to this crash. Every other game log I've got as a result of this crash is one of those two, so no more logs are attached.
There was no mods used.
The game was launched via Steam.

[posila]

Thanks for the report.
It should be fixed in 0.15.16