I loaded your "Test random artifacts (before studying the artifacts).rar" save game and debugged it.
The problem is that all weights on your artefacts are set to zero and in this case it will always chose the first one which is the gold artefact.

Can you double check the weights you set up in the map editor if they are really non-zero?
Maybe you forgot to save or something?

So the game just shut down for you?
Normally when the game crashes it does state it in the output_log and creates a separate crash log with memory dump, but here the output_log just ends without reporting a crash.
So it will be hard to track the cause down but the last line in log was:
"An unpooled VFX Object was destroyed, elements remaining in stack 1"

Which looks very similar to the crash reported here:
http://brightrockgames.userecho.com/topics/1006-crash-report/#

In both cases the VFX pooling system was doing the last log before it crashed.
So I guess we will have to look into this system to hunt the cause.

When you (or anyone reading this) get such a crash again, please attach your log again to this thread.
So far all logs files around the issue did fail to report the exact stack trace of the crash and I hope with more logs we get at least one which tells us more about the cause.

Cheers

I love Unity for reliably logging the cause of a crash:
"RtlLookupFunctionEntry returned NULL function. Aborting stack walk."

This means Unity had an internal issue when it was trying to log the stack trace of the crash.
Now we not know at all where it did came from.
Last log before crash was:
"Unmanaged pool object fx_potion_frostweaver(Clone) (PoolParty.VFXDeadTimer)"
But not sure if this is enough to track the issue down.

Was this happening only once or do you encounter crashes like this more often?

Tested it again and it worked fine, so either you are not updated or we need a save to see why it does not work for you.

This is correct.
So is there any issue or can we close this report?

It should be fixed in v1.4.0f11 and it was tested on the map linked by Nutter, where it was not working and we made it work.
Did you update to this version and if you did, can you upload a save game where it doesn't work for you?
Cheers

This is normally an issue with Steam it self.
Can you try to uninstall Steam Client and install it again?
(Your save games and other data is not impacted by this)

Hello Travis_rowl,
this is an issue of SteamWorks DRM check, only Steam can fix.
Please read here about a potential solution:
http://brightrockgames.userecho.com/topics/970-start-load-crash-rinse-and-repeat/

Alright we fixed it.
Now constructs placed on volcanic bridges can be sold properly.