Clipping Mask appearing in different illustrator versions

[lexiesignchamp]

I have a quick question.  I am noticing that if I design something in illustrator with no clipping masks and then one of the other designers I work with opens the same file on their computer all of a sudden there are a bunch of random clipping masks.

I have Illustrator 2019 and they have Illustrator 2017.  

I am attaching a file and a screen shot of what it looks like on my computer and then on his computer

Any thoughts on this? Do they need to update to the newest verison or is there a way around this?

Original FileCorrect layers created with version 2019Incorrect layers opened with 2017

[Larry G. Schneider]

The most logical reason is the person opening the file is accessing the PDF portion of the file. Are you both using the same version of AI?

[lexiesignchamp]

Hello! Yes we open and save our illustrator files as PDFs because our printers do not print ai files. We are not using the same version of Illustrator. I have Version 2019 and my coworkers have Version 2017. 

Do you know why the file changes when it is saved and opened as a PDF? 

[Larry G. Schneider · Accepted solution]

AI is NOT an all-purpose PDF editor. PDF is an output file format. When working with different versions of AI, it will always default to the PDF version of the file which needs the clipping masks to show items in the PDF correctly. Your best bet is for everyone to work in the same version of AI and not generate the PDF until submitting the file for print.