Links failing to work

I have recently experienced links between pdf's held in folders that I have sent by WevTransfer or Dropbox failing to work. Everything worked fine up to a week before Xmas but then everything failed to work. I have uploaded the latest versions of Sonoma and Adobe Acrobat Pro on my Apple Airbook but still fail to open.

I have spoken with Adobe support but they have failed to solve the problem as they could not share by computer due to errors.

any ideas anybody?

Thanks Gareth Turner