Unable to open narration in this presentatione

No matter which thing I click on - interaction, quiz, package - I get the message - The narration file for this presentation may be in use by another program or user, or it may be read only.

I used a different presenter file that I have as the base for this new one but I have saved this new one File/Save as.  Is this causing me problems?  It is a large deck of about 150 slides with video and such.  I can't even create a new quiz or package the file.  What to do?