This is probably an idiocyncracy with Steam itself. We did patch today, which might have interrupted the existing download.

Originally posted by cheiften98: It did it again. 20gb on install and its restarted back the start. No other game other thatn Ark does this. What am I supposed to do??

Please see: https://support.fatshark.se/hc/en-us/articles/360038458034--PC-Stuck-in-a-Steam-validation-update-installation-loop-