ForEachLoop missing from file

I have been having this error where I open up my project file and I have blueprints that will not compile because my “ForEachLoop” nodes break seemingly randomly. I have had this happen twice, and the first time I was able to replace each “ForEachLoop” and recompile. However, after teh second time this happened, I was unable to replace the “ForEachLoop” because it was not popping up as an option for a node to be used. I’ve had this issue within the Level blueprint and in the BP_MotionController blueprint as seen below. I think this may be a computer specific issue, because I am able to do the “replace all the for each loops” on a separate computer, but am unable to do so on the computer I received the error on. Is this an error because I am still using 4.17 and not 4.18? Any advice would be great, thanks!

It seems that updating to the newest version of Unreal, version 4.18 fixed my issues.