Skype for Business has stopped working at startup

Hi Stoynoff,

First, please be sure that the operating system and Office 2016 suits are the latest versions. You can open any Office 2016 application, such as Outlook 2016, to update the Office 2016 suits as the following steps: In Outlook 2016, navigate to FILE > Office Account > Update Options > Update now. Check if there is any improvement after upgrading. 

After installing the latest version, you may also try the following if the issue persists.

1. Hold the windows key + Letter ‘R’ from the keyboard to launch the Run command, paste “lync.exe /safe” in the open box to start Lync in safe mode and see if the issue persists.
2. Do an Online Repair for all your Office programs and see if it helps.

3. Even though you have reinstalled All Office apps, some cache files will remain. Please follow the steps below to clear the Skype for Business cache:

a. Navigate to the %localappdata%\Microsoft\Office\16.0\Lync folder.
b. Delete your sip profile folder
c. Go into the Tracing folder
d. Delete the all files, but not the folders

Based on your description, the issue may be related to the software conflict in your PC, you can also perform a clean boot and see if the issue can be fixed.

Please let me know the following after you tried all the steps above with no luck:

1. Does the Skype for Business client not even start or crash/hold on startup? A screenshot about the scenario will be better to understand the situation.
2. If you switch another Windows User Profile, does the issue persist?

Thanks,

Lance