Upon logging in, users receive multiple apex errors due to Salesforce critical update enablement.

Why do I receive multiple apex errors immediately after logging in to AdvoLogix/Salesforce after 8/8/2020?

Restrict Access to @AuraEnabled Apex Methods for Authenticated Users Based on User Profile

In the Salesforce Winter '21 release, a critical update was enforced that gives you more control over which authenticated users can access Apex classes containing @AuraEnabled methods.  When this update was activated, an authenticated user could access an @AuraEnabled Apex method only when the user's profile allowed access to the Apex class.

System administrators can manually modify each profile by assigning all AdvoLogix Apex classes or they can use the pre-packaged AdvoLogix permission set that will grant access to those classes.  The AdvoLogix permission sets contain default permission levels for both an admin and a user.  Be aware that the permission set(s) will grant permissions even to objects or fields the user may have hidden in the profile.

For additional information about this critical update and best practices, please review the resources below:

• Restrict Access to @AuraEnabled Apex Methods for Authenticated Users Based on User Profile (Update, Enforced)
• Critical Update: Ensure Users Have Access to @AuraEnabled Methods