fix (#16137)

code/modules/research/xenoarchaeology/artifact/effects/unknown_effect_forcefield.dm

@@ -38,6 +38,9 @@
 /datum/artifact_effect/forcefield/UpdateMove()
 	if(created_field.len && holder)
 		var/turf/T = get_turf(holder)
+
+		if(!T)
+			return
 		while(created_field.len < 16)
 			//for now, just instantly respawn the fields when they get destroyed
 			var/obj/effect/energy_field/E = new (locate(T.x,T.y,T))

html/changelogs/fluffyghost-fixartifactforcefieldeffect.yml

@@ -0,0 +1,41 @@
+################################
+# Example Changelog File
+#
+# Note: This file, and files beginning with ".", and files that don't end in ".yml" will not be read. If you change this file, you will look really dumb.
+#
+# Your changelog will be merged with a master changelog. (New stuff added only, and only on the date entry for the day it was merged.)
+# When it is, any changes listed below will disappear.
+#
+# Valid Prefixes:
+#   bugfix
+#   wip (For works in progress)
+#   tweak
+#   soundadd
+#   sounddel
+#   rscadd (general adding of nice things)
+#   rscdel (general deleting of nice things)
+#   imageadd
+#   imagedel
+#   maptweak
+#   spellcheck (typo fixes)
+#   experiment
+#   balance
+#   admin
+#   backend
+#   security
+#   refactor
+#################################
+
+# Your name.
+author: Fluffyghost
+
+# Optional: Remove this file after generating master changelog.  Useful for PR changelogs that won't get used again.
+delete-after: True
+
+# Any changes you've made.  See valid prefix list above.
+# INDENT WITH TWO SPACES.  NOT TABS.  SPACES.
+# SCREW THIS UP AND IT WON'T WORK.
+# Also, all entries are changed into a single [] after a master changelog generation. Just remove the brackets when you add new entries.
+# Please surround your changes in  double quotes ("), as certain characters otherwise screws up compiling. The quotes will not show up in the changelog.
+changes:
+  - bugfix: "Fixed the artifact forcefield effect, which could runtime if it didn't find a turf."