Not sure what has went wrong but I'm not able to execute OLE Automation Procs like "sp_OACreate", "sp_OAMethod" etc. which was working fine for past week.
The account\login I'm using has "SYSADMIN" privilege. Also, Configuration values for "Ole Automation Procedures" has already been set to 1.
Tried with several SQL as well as Windows Login with "sysadmin" permissions but to no avail. Even with sysadmin account getting the following error:
Msg 229, Level 14, State 5, Procedure sp_OACreate, Line 1
The EXECUTE permission was denied on the object 'sp_OACreate', database 'mssqlsystemresource', schema 'sys'.
Msg 229, Level 14, State 5, Procedure sp_OAMethod, Line 1
The EXECUTE permission was denied on the object 'sp_OAMethod', database 'mssqlsystemresource', schema 'sys'.
Msg 229, Level 14, State 5, Procedure sp_OAMethod, Line 1
The EXECUTE permission was denied on the object 'sp_OAMethod', database 'mssqlsystemresource', schema 'sys'.
Msg 229, Level 14, State 5, Procedure sp_OAGetProperty, Line 1
The EXECUTE permission was denied on the object 'sp_OAGetProperty', database 'mssqlsystemresource', schema 'sys'.
Even tried with adding the "sysadmin" accounts as DBO on master and giving "execute" permissions to all above Extended SPs (knowing it won't going to help much).
Command to Rebuild these Ex-SPs is also failing.
exec sp_addextendedproc N'sp_OACreate', 'odsole70.dll'
exec sp_addextendedproc sp_OADestroy, 'odsole70.dll'
exec sp_addextendedproc sp_OAGetErrorInfo, 'odsole70.dll'
exec sp_addextendedproc sp_OAGetProperty, 'odsole70.dll'
exec sp_addextendedproc sp_OAMethod, 'odsole70.dll'
exec sp_addextendedproc sp_OASetProperty, 'odsole70.dll'
exec sp_addextendedproc sp_OAStop, 'odsole70.dll'
Error:
Msg 208, Level 16, State 77, Procedure sp_addextendedproc, Line 42
Invalid object name ' '.
No changes were made on SQL Level however few changes were made on OS level like, Creating and deleting SPN for the server in domain (for SQL Service Account), adding and removing SQL Service Account from following local windows account group.

Currently there is no SPN exists for the server and the SQL Services are running with windows domain account which is administrator on server but not part of any other group.
Kindly assist me as I'm neither able to find anything related to it on web nor any steps in this regard are working.