Suddenly cant launch Fusion 360 due to Certifcate Verification

[Anonymous]

After using Fusion 360 flawlessly for about 7 months, I suddenly cant even launch Fusion 360.  At launch, I get a pop up window in lower Right that says "Server Verification Warning: Unable to validate a security certificate. Many times this can be triggered by proxy servers, security software, or out of date OS patches.  Please visit the 'Network/Server Verification' preference page if you would like to change this setting."  At that point, Fusion360 pops up a window that says Fusion was unable to save sufficient data for Offline mode and needs to go Online.  Please make sure you have a working Internet connection to continue."  Which is followed by "Cannot switch to online mode either. Please check your internet connection.  Application will exit now."  And it closes.  No question that I do have a valid and active internet connection. 

Additional Info:

Under C:\Users\{user}\AppData\Local\Autodesk\Autodesk Fusion 360\

I have 2 folders that have alphanumeric characters.  There is also a folders named: Electron, logs, Unknownuser

I have tried these steps:

1. completed all pending Windows Updates.  -- no luck

2. Turn off Windows Defender Firewall.  --no luck

3. Removing Fusion 360 and reinstalling.  --no luck

4. Deleting the LoginState.xml file.  --this allows Fusion to stay on long enough for me to login.  then repeats the messages about no internet connection and exits.

How could things go from so good to so bad, so quickly?  Please help...

[jhackney1972]

Take a look at these two webpages and see if you can get the needed information to fix your problem.  Webpage 1,  Webpage 2

[Anonymous · Accepted solution]

Thanks for your response!!

I think that I now have it resolved after much trial and error.

Here are the things that helped. (I am using Windows 10 on a personal computer at home)
1. I opened 'Windows Defender Firewall with Advanced Security' under Inbound Rules.
For every instance of Autodesk Fusion 360 and FusionLauncher.exe that was previously set to Private Profile, I changed the profile to Private, Public.
This step at least let me open Fusion 360 in offline mode.

2. Then as suggested in the Webpage 2 your referenced, within Fusion 360, in the preference menu under my name in upper right, I went to Network and change Automatic to 'No Proxy'. Then within 30 seconds Fusion 360 came back online and all my projects came back.

Hopefully, it stays resolved.

I really appreciate your help.😀