I cannot find a relevant item in Preferences by which this grey blotch is suddenly appearing on .pdf documents viewed in Acrobat Professional 9.5.5. It seems to be obscuring logos as if it is trying to obscure a layer.
Go to Edit - Preferences - Page Display and tick "Show large images".
On Sun, Sep 24, 2017 at 12:16 AM, mark hg70025354 <email@example.com>
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