pdf file format is having difficulties. Bad Parameters

This has been happening on files with transparency masks. I will create a transparent gradient mask using the transparency window while using spot colors, mind you and I get an error message when attempting to save a PDF compatible illustrator file. I had to delete the mask and build my file a different way which is fine but it has always worked in previous versions. There has been a copius amount of bugs in this latest release and it is truly frustrating. I hope you guys can get it together or use some of the Billions of dollars you make annually to hire someone who can.