Error opening specified object -2147016656 assigning user rights

Error opening specified object –2147016661 trying to extend AD schema / assign rights using the adschema.exe

Check the syntax is correct and the CN (or OU) and DC’s are correct.

• If assigning rights to OU’s that are not the built in ""Users"" container, use the following syntax (instead of CN=, use OU=)

  OU=London,DC=company,dc=com

• If assigning rights to the built in Users container, user the following syntax (instead of OU=, use CN=)

  CN=Users,DC=company,dc=com

• Check the specified container exists.

• Check your spelling.

• Check your rights to modify the schema (e.g. schema admin)

• Check the domain name (open Active Directory Users and Computers and check you have all instances of dc= in the path)