I was able to correct this error by removing the sync rule function that added the CRLF(), by creating a Set, Work Flow, MPR. The Workflow uses MIMWAL Update Resource Activity, however the above ReplaceString causes errors:
System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary. at System.ThrowHelper.ThrowKeyNotFoundException() at System.Collections.Generic.Dictionary`2.get_Item(TKey key) at etc...
This below syntax worked, but I had to test is many times because it's not documented anywhere;
ReplaceString([//Target/Facility]," | ",""+CRLF()+"") -> [//Target/FacilityView]
Also, the target Facility is a single valued non-indexed string (very long) that goes to a multi-valued non-indexed string, and the RCDC displays these great now using UocCommonMultiValueControl. Hope this helps someone in the future. Been spending
long hours trying to figure this one out.