URL: web.skype.com
Browser / Version: Mozilla Firefox 46.0 (x64)
Operating System: Ubuntu 16.04 LTS (x64)
Problem type: Something else - I'll add details below

Steps to Reproduce

1. Navigate to: web.skype.com
2. Login with Firefox on Ubuntu 16.04

Expected Behavior:
Ability to call contacts expected.
Actual Behavior:
Call button is greyed out. Contacts cannot be called.

Workaround:
Change user string agent to Microsoft Edge on Windows. Contacts can then be called flawlessly.

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