I was given a .ai file to do a simple change. Illustrator won't let me save to .ai
After saving the file this error message occurred:
When spot colours are used with transparency, changing them to process colours outsitde of Illustrator can generate unexpected results.
An Unknown error has occured
These warnings also showed.
"Only fonts with permission bits will be embedded." "The Document Raster Effects is 72ppi or less."