Is anyone else having issues with Lightning Experience in Winter '18 being slow again? I haven't seen anything in known issues, but our Sandbox testing is going poorly. Turning off the new branding and themes marginally improved performance, but it's still significantly worse than Summer '17 is in Production.
 
We've noticed frequent crashes, as many as 6 times in a single session, 30 seconds or more to navigate to a different object tab, and caching issues which result in the page displaying old data if you refresh right after an edit.
 
These issues happen for us on both 100% standard pages and pages customized with the lightning app builder to include a mix of custom and standard components.
 
Any recommendations on how to improve performance would be greatly appreciated!

We are having an issue where our custom Lightning components that were developed, fully tested, and working using the new Salesforce Locker Service security requirements with Locker Service enabled in Winter '17 and Spring '17 APIs versions 38.0 and 39.0 have all broken when upgraded to the new Summer '17 API 40.0 Locker Service enforcement.

What is the difference between enabling Locker Service for the Winter '17 and Spring '17 releases and the new Summer '17 enforcement in API version 40.0?

I can't seem to find any documentation that explains the difference in the security requirements between the two, only documentation on what is required for Locker Service, which hasn't changed since it was initially released last year. This is the documentation we used to prepare for Locker Services: https://developer.salesforce.com/blogs/developer-relations/2016/04/introducing-lockerservice-lightning-components.html

Here are the errors we are receiving, any insight would be much appreciated as these errors are extremely vague and do not directly reference our component markup:
Uncaught render threw an error in 'markup://aura:html' [Failed to execute 'appendChild' on 'Node': parameter 1 is not of type 'Node'.]
AND
Uncaught render threw an error in 'markup://aura:expression' [Assertion Failed!: Descriptor for Config required for registration : undefined]

Thanks,
Mai

I'm receiving the following error on challenge #6 of the Lightning Superbadge:

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Delete failed. First exception on row 0 with id 0035000002hUBgRAAW; first error: DELETE_FAILED, Your attempt to delete Sam the ninja could not be completed because it is associated with the following adventure packages.: null, null : []

Looking at the Developer Console, it looks like the code which checks the system is forgetting to delete the Adventure Package records before deleting the Contact. Has anyone else run into this issue?

Thank you!

I'm receiving the following error on challenge #6 of the Lightning Superbadge:

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Delete failed. First exception on row 0 with id 0035000002hUBgRAAW; first error: DELETE_FAILED, Your attempt to delete Sam the ninja could not be completed because it is associated with the following adventure packages.: null, null : []

Looking at the Developer Console, it looks like the code which checks the system is forgetting to delete the Adventure Package records before deleting the Contact. Has anyone else run into this issue?

Thank you!

I'm receiving the following error on challenge #6 of the Lightning Superbadge:

Challenge Not yet complete... here's what's wrong: 
There was an unexpected error in your org which is preventing this assessment check from completing: System.DmlException: Delete failed. First exception on row 0 with id 0035000002hUBgRAAW; first error: DELETE_FAILED, Your attempt to delete Sam the ninja could not be completed because it is associated with the following adventure packages.: null, null : []

Looking at the Developer Console, it looks like the code which checks the system is forgetting to delete the Adventure Package records before deleting the Contact. Has anyone else run into this issue?

Thank you!