Additional features, settings, or issues not covered by specific Microsoft Teams categories
delete my cache didn't help on my mac - even the symptom is the same -> small white window with no content in it ??
Log shows:
2020-02-19 18:59:19.268 Teams[17949:349130] ADD: failed to create cache dictionary at path=/Users/####/Library/Caches/com.microsoft.teams. key=0x7fa8666a6850
2020-02-19 18:59:19.280 Teams[17949:349130] ADAL 2.6.9 Mac 10.14.6 [2020-02-19 17:59:19 - AFEDFAAF-14F8-41CD-9999-90CE7275DAAD] ERROR: Error raised: (Domain: "ADAuthenticationErrorDomain" Code: AD_ERROR_SERVER_USER_INPUT_NEEDED ProtocolCode: "(null)"