@Anonymous can you try the below steps.
- Close Fusion360.
- Delete files mentioned below and then try to login Fusion.
Windows
%APPDATA%\Autodesk\Neutron Platform\Options\NMachineSpecificOptions.xml
%APPPDATA%\autodesk\Neutron Platform\Options\<O2ID>\NGlobalOptions.xml
%TEMP%\autodesk\BrowserCache
%LOCALAPPDATA%\Autodesk\Web Services\Loginstate.xml
%LOCALAPPDATA %\Autodesk\Web Services \Autodesk Fusion 360\<Build ID>\WebServicesCache.xml
%LOCALAPPDATA%\Autodesk\Autodesk Fusion 360\<O2ID>\NsCloudBrowserCache_myhub.dat
%LOCALAPPDATA%\Autodesk\Autodesk Fusion 360\<O2ID>\ NsCloudBrowserCache_autodesk****.dat
% LOCALAPPDATA %\Autodesk\Autodesk Fusion 360\<O2ID>\P.Login\jobs.json.lck
% LOCALAPPDATA %\Autodesk\Autodesk Fusion 360\<O2ID>\P.Login\jobs.json
% LOCALAPPDATA %\Autodesk\Autodesk Fusion 360\<O2ID>\W.Login\Q
% LOCALAPPDATA %\Autodesk\Autodesk Fusion 360\<O2ID>\W.Login\UploadQueuedFileList.xml
MacOS
~Library/Application Support/Autodesk/Neutron Platform/Options/NMachineSpecificOptions.xml
~Library/Application Support/Autodesk/Neutron Platform/Options/<O2ID>/NGlobalOptions.xml
$TMPDIR/Autodesk BrowserCache
~Library/Application Support/Autodesk/Web Services/Loginstate.xml
~Library/Application Support/Autodesk/Web Services/ Autodesk Fusion 360/<Build ID>/WebServicesCache.xml
~Library/Application Support/Autodesk/Autodesk Fusion 360/<O2ID>/NsCloudBrowserCache_myhub.dat
~Library/Application Support/Autodesk/Autodesk Fusion 360/<O2ID>/NsCloudBrowserCache_autodesk****.dat
~Library/Application Support/Autodesk/Autodesk Fusion 360/<O2ID>/P.Login/jobs.json.lck
~Library/Application Support/Autodesk/Autodesk Fusion 360/<O2ID>/P.Login/jobs.json
~Library/Application Support/Autodesk/Autodesk Fusion 360/<O2ID>/W.Login/Q
~Library/Application Support/Autodesk/Autodesk Fusion 360/<O2ID>/W.Login/UploadQueuedFileList.xml
Hope it helps.
Regards,
Rushikesh Kadam
Senior QA Engineer
Quality Assurance
Autodesk, Inc.