3815145 - What does different Action commands in an Travel Profile API 2.0 xml message mean?

We are trying to update profiles by sending data through Travel Profile API 2.0, but keep getting an error message. The first line of the log looks something like this. Why are we getting the error for trying to update profiles in Concur?

<ProfileResponse Status="Active" LoginId="xxxxxxxxx@xxx.com" Action="Create" xmlns:xsi="............................."

Error: Invalid User (EC1)

We are getting an error as 'Invalid User (EC1)' in Travel Profile API 2.0 , KBA , CON-CA-USP , User Profile , Problem