Outlook blocks access to the following attachment.

Hello,
Barnabe0057,
this response is valid in the case where you receive a message with an attachment.
In my case, it's when I send an attachment that I created myself!!!
I still found a solution that doesn't completely satisfy me, but it allows me to view the attachments I send to my clients or suppliers: I noticed that if I put a "." (dot) at the end of my attachment name, OUTLOOK considers my attachment as "potentially dangerous," whereas if I don't put anything at the end, my attachment is clearly visible in my email.
This wasn't a problem before the last monthly patch from Microsoft.
If this can help someone else while waiting for a fix.
JC

Hello,

Click on Start, Run, type regedit in the Open box, and then click OK.
Find one of the following registry subkeys and click on it:

Outlook 2010 (version 14.0)
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security or: HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\14.0\Outlook\Security

In the Edit menu, point to New, then click on DWORD Value.
Type AllowAttachByRef as the name for the DWORD value, and then press Enter.
Right-click on AllowAttachByRef, and then click Modify.
In the Value data box, type 1, and then click OK.
Exit the Registry Editor, and then restart the computer.

Important The AllowAttachByRef registry entry only re-enables ATTACH_BY_REFERENCE and ATTACH_BY_REF_ONLY attachments. ATTACH_BY_REF_RESOLVE attachments are still blocked.

Hello and thank you for your response BARNABE0057, but I had already seen that.
But my problem is different; the PDF files I receive, I can open them, but not the ones I send. My contacts receive the attachment in the email and open it without any problem, but in my "Sent Items" folder, the email is there, but with the message "Outlook has blocked access to the following potentially dangerous attachments" even though I created this email and this attachment myself???
And this started happening after last Tuesday's Windows updates.