References suddenly scrambled

After a long day of working on a document of 15000 words, I have noticed that the references have been scrambled. They are often one reference too late (i.e. the correct reference appears the next time I quote someone), but I can’t see a very specific pattern. Is there a way to fix this? 

Contact (CALL) Tech support.  I understand they have tools to fix this glitch.  

www.endnote.com/support 

Is there a number we can call from the UK without paying international rates? (Bilaney Consultants are not answering)