From the Autodesk knowledge Network

Scheduled Down Time: We will be performing a maintenance update from 8:30-10:30 pm PT on Friday, September 20. Some features and functionality will be unavailable during this time, but no action is required. 

Issue:

Autodesk software and services requiring sign in (or identity-based access) will be unavailable beginning at 8:30 pm PDT on Friday, September 20 (3:30 am GMT, Saturday, September 21). 

Solution:

To continue to improve the resiliency and scalability of our products, Autodesk will perform a maintenance update, which will result in some services being down for approximately two hours. No action is required. 

You can still use your software during this maintenance window but the following functions will be unavailable: 

Products and product features that rely on cloud access: All users online during this maintenance window will experience intermittent issues with product access. 

Autodesk Account functions, including account creation, sign-in, and deletion; user management functionality, such as adding/removing users; and support case creation. 

Support through Autodesk Knowledge Network: 

Contact Support 
Autodesk Forums 
In-product help 

Autodesk Virtual Assistant (AVA) 

Autodesk Store: New subscription/service purchase delay 

Autodesk University registration 

Software Trial: Product download and use 

Forge: API-based automations may fail 

Education/Institution licenses: No new account creation or software download 

Again, we anticipate the maintenance window to last up to two hours. We appreciate your patience and understanding. 

https://knowledge.autodesk.com/search-result/caas/sfdcarticles/sfdcarticles/September-2019-Scheduled-Down-Time-for-Maintenance.html