I just had this question yesterday so I thought I would share:

ISSUE = When importing original file into a Ipro project, does Ipro also require that there be images present? We’re trying to load an LFP of only original files with no images and it doesn’t seem to be working.

DETAILS = Quick answer = NO; images not required for native file review in Ipro Viewer

however the LFP file needs to have 2 commands per record – it sounds like you are loading only the 1 (OF). Details below and small samples attached. This information can be loaded via one single LFP or separate LFP files. (just load the IM lines or IM LFP first) Please let me know if this works for you or if a quick chat will help.

LFP commands needed =

IM command (creates the database record in Ipro) (Image Master)
OF command (loads path to native file in Ipro) (Original File)

Example =

OF,ESI_00000005,\\server name\natives\my excel file.xlsx