And now my documents won´t print to PDF anymore, because the ICC says that I have missing links, documents, etc. What can I do?
Are the links up to date? If not, you need to fix them.
The links are all pictures. So pics which i put in the document myself. No weblinks or something. Do I need to put all pics in the document again?
When you use File > Place.. to add pictures you are creating links to those pictures. If those images are subsequently moved or altered, the links will become lost or show as modified. Links will also be lost if you move the file to a new computer that has no access to the original link locations. It is up to you to make sure the internal links are OK.