Preview crashes when searching a word

Ive imported a 27 page pdf into preview. I tried to search one word "recorded" that works fine. I try to search the word "recording" and before i even press search preview crashes. Every time crashes no idea why, restarts preview type in the word with "ing" and again crashes. I can report that today this error has gone, the document is now able to be searched so I cant reproduce this error. No restart has been performed but I did shut down Safari and restart that because of a skype for business install.