Right, this is a strange issue. I have a 233 page PDF document that I'm constantly referring to whilst studying for an exam on friday. When I'm looking for particular things I hit cmd+f and search the term. This has been working fine up until now. For some reason, search doesn't work. At first I thought it was just broken in some way but if I search for any single letter - such as 'm' it highlights 'd', searching for 'd' highlights 'o' etc. If I copy text from the PDF it now comes out as jibberish. Eg - "CS304 - Operating Systems & System Software" pastes as "!"#$%&'()*+,-./&"01,)21&3&"01,)21& "45,6+*)" Has anyone got any idea why this has just started happening? It's only this PDF too.
Any chance your copy is corrupted? Have you tried re downloading it/asking a classmate for another copy?
I've got hold of another copy of the same file and it's working fine. I'm still interested to know what caused it and if there is anyway to recover the original, just incase it happens to something again and I can't get another copy.