I downloaded a pdf reader. After that, I can not read and save invoices. This is mistake? Or is t

[emfirion]

I downloaded a pdf reader. After that, I can not read and save invoices. This is mistake? Or is this a violation on my part, by me, of the user agreement? 

[try67]

Use Adobe Acrobat Reader to view the files.

[emfirion]

the problem is that even after removing this program, the error now remains.