# Schema extension errors
<a name="ms_ad_troubleshooting_schema"></a>

The following can help you troubleshoot some error messages you might encounter when extending the schema for your AWS Managed Microsoft AD directory.

## Referral
<a name="referral"></a>

**Error**  
*Add error on entry starting on line 1: Referral The server side error is: 0x202b A referral was returned from the server. The extended server error is: 0000202B: RefErr: DSID-0310082F, data 0, 1 access points \$1tref 1: ‘example.com' Number of Objects Modified: 0*

**Troubleshooting**  
Ensure that all of the distinguished name fields have the correct domain name. In the example above, `DC=example,dc=com` should be replaced with the `DistinguishedName` shown by the cmdlet `Get-ADDomain`.

## Unable to read import file
<a name="unabletoread"></a>

**Error**  
*Unable to read the import file. Number of Objects Modified: 0*

**Troubleshooting**  
The imported LDIF file is empty (0 bytes). Ensure the correct file was uploaded.

## Syntax error
<a name="syntaxerror"></a>

**Error**  
*There is a syntax error in the input file Failed on line 21. The last token starts with 'q'. Number of Objects Modified: 0*

**Troubleshooting**  
The text on line 21 is not formatted correctly. The first letter of the invalid text is `A`. Update line 21 with valid LDIF syntax. For more information about how to format the LDIF file, see [Step 1: Create your LDIF file](create.md).

## Attribute or value exists
<a name="attributeorvalue"></a>

**Error**  
*Add error on entry starting on line 1: Attribute Or Value Exists The server side error is: 0x2083 The specified value already exists. The extended server error is: 00002083: AtrErr: DSID-03151830, \$11: \$1t0: 00002083: DSID-03151830, problem 1006 (ATT\$1OR\$1VALUE\$1EXISTS), data 0, Att 20019 (mayContain):len 4 Number of Objects Modified: 0*

**Troubleshooting**  
The schema change has already been applied.

## No such attribute
<a name="nosuchattribute"></a>

**Error**  
*Add error on entry starting on line 1: No Such Attribute The server side error is: 0x2085 The attribute value cannot be removed because it is not present on the object. The extended server error is: 00002085: AtrErr: DSID-03152367, \$11: \$1t0: 00002085: DSID-03152367, problem 1001 (NO\$1ATTRIBUTE\$1OR\$1VAL), data 0, Att 20019 (mayContain):len 4 Number of Objects Modified: 0*

**Troubleshooting**  
The LDIF file is trying to remove an attribute from a class, but that attribute is currently not attached to the class. Schema change was probably already applied.

**Error**  
*Add error on entry starting on line 41: No Such Attribute 0x57 The parameter is incorrect. The extended server error is: 0x208d Directory object not found. The extended server error is: "00000057: LdapErr: DSID-0C090D8A, comment: Error in attribute conversion operation, data 0, v2580" Number of Objects Modified: 0*

**Troubleshooting**  
The attribute listed on line 41 is incorrect. Double-check the spelling.

## No such object
<a name="nosuchobject"></a>

**Error**  
*Add error on entry starting on line 1: No Such Object The server side error is: 0x208d Directory object not found. The extended server error is: 0000208D: NameErr: DSID-03100238, problem 2001 (NO\$1OBJECT), data 0, best match of: 'CN=Schema,CN=Configuration,DC=example,DC=com' Number of Objects Modified: 0*

**Troubleshooting**  
The object referenced by the distinguished name (DN) does not exist.