Adobe Acrobat Reader 2026.001.21789 (64 Bit) does not open tel: links.

Thanks for sharing these detailed test results. The comparison between Protected Mode and Enhanced Security makes the cause much clearer, especially since Protected Mode is the setting affecting tel: links. The diagnostic logs should help Adobe identify whether this is a security restriction or a regression in the current version.

Hi ​@Ronny5F98 ,

Hope you are doing well and thanks for the detailed writeup and for testing across three machines, that rules out a lot of the usual culprits.

Since https: and mailto: links pass through fine but tel: stops right after "Allow," this looks like Acrobat isn't handing the tel: scheme off to the OS the same way it does for the other two.

A few things to check:

• Does the same PDF, opened in Acrobat Pro (not just Reader), show the same behavior?
• In Preferences (Ctrl,Cmd+K) > Trust Manager, does the "Internet Access from PDF Files outside the web browser" section show anything unusual, or is it possible to change those settings at all on your setup? https://helpx.adobe.com/th_th/acrobat/current/allow-or-block-links-internet.html 
• Does turning off Enable Protected Mode/Enhanced Security under Preferences (Ctrl,Cmd+K) > Security (Enhanced) change anything after a restart? Details on those settings here: https://helpx.adobe.com/in/acrobat/using/enhanced-security-setting-pdfs.html . This is a long shot given https and mailto already work fine, but it's quick to rule out.

If none of that changes it, please share a small video recording of the steps you are taking and the issue as it occurs so we can get this cheked further at our end.
 

Let me know how it goes.

~Amal