Outlook pdf issue attachment preview

Dear Community, 

Our logistic deparment has the following issue.

Suddenly they can't preview document - they get the following error

• We have followed the instruction at https://support.microsoft.com/en-us/office/outlook-pdf-preview-error-this-file-cannot-be-previewed We followed every step expect Toys app, collegae  has not installed it. 
• i have re-send this email to other email adres in there i get preview and my collega not.

I hope you can give me some hints&tip.

Kind regards, 

Qeis Maksoudi