Power Pages or Power Portal Captcha not rendering when embedded in another website / basic or multistep form redirection not working

 When a Portal page is embedded within another website as an Iframe, the cookies used by the portal Page might be treated as a third party site cookies by the browser.

It is recommended that the domain name be a sibling or a child of the domain name of the site where you're embedding the portal in an iframe Example: your root website is www.contoso.com, the portal domain name should be portal.contoso.com

Reference: https://learn.microsoft.com/en-us/power-apps/maker/portals/embed-portal-website

CRM 2011 not rendering on the browser, inspite of opening in the compatibility View

Even after compatibility view, the CRM 2011 doesn't open, on load- and opening the debugger says "mainscript is undefined"

One of the scenarios this would happen if the Main Folder of the CRM is secured and has no access provided to the User opening CRM.
To resolve this, navigate to the drive where CRM was installed , navigate to the main folder and select Security, provide Read access to the Users,

User creation On Premise "Attempting to create a user with a domain logon that does not exist"

This can happen in some scenarios of a valid Username as below:

1. Trust is not established between the CRM Server domain and the User Domain
2. The User is not present is not active in Active Directory

3. Duplicate entry of User is present with same user Name in the Active Directory (Can happen in scenarios where Post deactivation, same Username is created again)

To resolve the issue, 

•  Correct the User Name in the ACtive Directory by deleting the entry corresponding to the inactive username.

If it is not feasible to make the correction in the Active Directory, 

• Temporarily turn the AutoGroupManagementOff to 1 in the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM in CRM FrontEnd
  (This is by default 0 - And during any User creation in CRM they are automatically added to the Reporting Group and User Group)
• Create User in CRM
• Add the User manually to the ReportingGroup and the UserGroup of the corresponding CRM AD Group.
  
  For details refer: 

For details refer: https://community.dynamics.com/crm/f/microsoft-dynamics-crm-forum/167494/issue-in-creating-a-user-in-crm-2011/411072