How to Fix Error on Outlook: "The request failed. Please try again. Make sure that you are signed into Skype for Business."

Symptoms:


When attempting to create a Skype meeting within Microsoft Outlook I am receiving the following error:

"The request failed. Please try again. Make sure that you are signed into Skype for Business."

Workaround:


It seems to be pertaining to the auto complete cache. clearing this cache using one of the following methods listed below:

• manually clearing it from the outlook options menu --> mail --> Empty Auto-Complete List 

• Or by starting outlook with the /cleanautocompletecache switch. 

• Or to create the following registry key: 

1. Subkey location: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Lync\AddinPreferenceDWord
2. Name: RecipientResolutionMode
3. Value data (decimal): 2