CRM 2015 – Web Service Error Codes

 Below is a link to the Microsoft page with all the error codes and descriptions that can be thrown by CRM web services.  

 
https://msdn.microsoft.com/en-us/library/gg328182.aspx 
 Few examples below:

<crmerror>
<ErrorId>80048531</ErrorId>
<ManagedErrorName>CustomImageAttributeOnlyAllowedOnCustomEntity</ManagedErrorName>
<ErrorMessage>A custom image attribute can only be added to a custom entity.</ErrorMessage>
</crmerror>
<crmerror>
<ErrorId>80048530</ErrorId><ManagedErrorName>SqlEncryptionSymmetricKeyCannotOpenBecauseWrongPassword</ManagedErrorName>
<ErrorMessage>Cannot open encryption Symmetric Key because the password is wrong.</ErrorMessage>
</crmerror>

Hope it helps.