Hi, I'm just designing my first mag for a client and I have two queries.
The first is an indesign error message query and the second a prepress query.
1.When I output as small file (for proofing purposes) size I get a transparency message. (See attached screen grab of indesign message.) I don't know what it means and whether this will effect printing in any way if I just ignore it ....
Also, one one spread where I have the warning I have an image that goes across the spread. The printer has said that the sky in the image on the right hand page side is different in colour to the sky slightly on the left hand page and has asked if I have put a transparent object on it?? When I view the spread in adobe it looks fine but on the printers prepress system there is a slight difference.
Are the two things connected or am I just worrying over nothing :-) Advice needed as go to press next week and don't want any nasty surprises for the client.
Working in Indesign CC.
2. When I uploaded a few test pages to their prepress system I got some warnings regarding image resolution which I understand, but there is a warning for something called:COLOURSPACE ICCBASED was used and COLOURSPACE RGBBASED was used. 
I have no idea what that is? Can anybody help explain that? See 2nd image attached for pre press error message.
Thanks!