Acrobat Pro is trying to convert any documents attached to emails

Good afternoon, 

I recently downloaded/updated to Acrobat Pro and now whenever I want to download email attachments which may be excel, word format (not PDFs). Acrobat appears to be the default program for this and tried to convert them which doesn't work obviously. I can't work out why it has started happening now. Today I clicked on a link to download a .ics file and Acrobat tried to convert this to a PDF?

Any ideas?