Item branch record with no primary location assigned P41024

 We have several items which have item branch location records that are all designated as S for secondary.  We do not know why they were not created with a Primary location assigned.  We have tried the option of "Change Primary" but apparently it looks for a Primary location to be in place before it can switch the P designation to another location.  Any thoughts on what could cause this or how to assign a Primary location to these SKUs now is appreciated.