Pasted links into pptx.

[Excelhatesme]

I have a multipage work book (xlsx) and a single sheet powerpoint document. I have pasted data from the workbook into the pptx using paste special/paste link/object. Having saved both in the same location, once I reopen the pptx and click "update links" I receive the following message; "Some linked files were unavailable and can't be updated. Try to restore the links by clicking the MO button, pointing to Prepare and then click Edit Links to Files". I have checked these links and they are routed to the correct location.

The excel doc was protected by sheet with only a small number of data cells unlocked. I undid this and it made no difference.

I deleted the powerpoint and rebuilt it again from scratch but it still did not update. Advice please.