The special characters in the first element name are causing issues. If you change:
{"{http://www.ebayclassifiedsgroup.com/schema/ad/v1}ads-search-options": {to
{"httpwwwebayclassifiedsgroupcomschemaadv1_ads-search-options": {
(remove '{', '}', ':' and '/') it seems to parse to XML without a problem.
<httpwwwebayclassifiedsgroupcomschemaadv1_ads-search-options>
<declaredType>com.ebay.ecg.api.spec.v1.schema.ad.AdsSearchOptions</declaredType>
<globalScope>true</globalScope>
<name>{http://www.ebayclassifiedsgroup.com/schema/ad/v1}ads-search-options</name>
<nil>false</nil>
<scope>javax.xml.bind.JAXBElement$GlobalScope</scope>
<typeSubstituted>true</typeSubstituted>
<value>
<adStatus>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<supported-value>
<e>
<localized-label>Active</localized-label>
<value>ACTIVE</value>
</e>
<e>
<localized-label>Delayed</localized-label>
<value>DELAYED</value>
</e>
<e>
<localized-label>Expired</localized-label>
<value>EXPIRED</value>
</e>
<e>
<localized-label>Deleted</localized-label>
<value>DELETED</value>
</e>
<e>
<localized-label>Pending</localized-label>
<value>PENDING</value>
</e>
</supported-value>
<type>ENUM</type>
</adStatus>
<adType>
<deprecated>false</deprecated>
<localized-label>Offer Type</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<supported-value>
<e>
<localized-label>Offered</localized-label>
<value>OFFERED</value>
</e>
<e>
<localized-label>Wanted</localized-label>
<value>WANTED</value>
</e>
</supported-value>
<type>ENUM</type>
</adType>
<address>
<deprecated>false</deprecated>
<search-param>unsupported</search-param>
<since>1.0</since>
<type>STRING</type>
</address>
<attributes/>
<categoryId>
<deprecated>false</deprecated>
<localized-label>Category</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
</categoryId>
<distance>
<deprecated>false</deprecated>
<localized-label>Distance</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>LONG</type>
</distance>
<distanceUnit>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<supported-value>
<e>
<localized-label>Kilometre</localized-label>
<value>KM</value>
</e>
</supported-value>
<type>ENUM</type>
</distanceUnit>
<email>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>STRING</type>
</email>
<excludeExternalSource>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
</excludeExternalSource>
<histograms>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>in</search-style>
<since>1.7</since>
<supported-value>
<e>
<value>CATEGORY</value>
</e>
<e>
<value>LOCATION</value>
</e>
<e>
<value>ATTRIBUTE</value>
</e>
</supported-value>
<value/>
</histograms>
<histogramsExpand>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>in</search-style>
<since>1.7</since>
<supported-value>
<e>
<value>CATEGORY</value>
</e>
<e>
<value>ATTRIBUTE</value>
</e>
</supported-value>
<value/>
</histogramsExpand>
<latitude>
<deprecated>false</deprecated>
<search-param>unsupported</search-param>
<since>1.5</since>
<type>DECIMAL</type>
</latitude>
<locale>en_AU</locale>
<locationId>
<deprecated>false</deprecated>
<localized-label>Location</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
</locationId>
<longitude>
<deprecated>false</deprecated>
<search-param>unsupported</search-param>
<since>1.5</since>
<type>DECIMAL</type>
</longitude>
<maxPrice>
<deprecated>false</deprecated>
<localized-label>Max Price</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>DECIMAL</type>
</maxPrice>
<minPrice>
<deprecated>false</deprecated>
<localized-label>Min Price</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>DECIMAL</type>
</minPrice>
<modAfter>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.7</since>
<type>DATETIME</type>
</modAfter>
<modBefore>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.7</since>
<type>DATETIME</type>
</modBefore>
<page>
<deprecated>false</deprecated>
<localized-label>Page</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>LONG</type>
</page>
<pictureRequired>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.6</since>
<type>BOOLEAN</type>
</pictureRequired>
<priceCurrency>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>STRING</type>
</priceCurrency>
<priceType>
<deprecated>false</deprecated>
<localized-label>Price</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<supported-value>
<e>
<localized-label>Free</localized-label>
<value>FREE</value>
</e>
<e>
<localized-label>Negotiable</localized-label>
<value>PLEASE_CONTACT</value>
</e>
<e>
<localized-label>Amount</localized-label>
<value>SPECIFIED_AMOUNT</value>
</e>
</supported-value>
<type>ENUM</type>
</priceType>
<q>
<deprecated>false</deprecated>
<localized-label>Keyword</localized-label>
<read>supported</read>
<search-param>optional</search-param>
<search-response-included>supported</search-response-included>
<search-style>eq</search-style>
<since>1.0</since>
<type>STRING</type>
<write>unsupported</write>
</q>
<size>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>LONG</type>
</size>
<sortType>
<deprecated>false</deprecated>
<localized-label>Sort Type</localized-label>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.5</since>
<supported-value/>
<type>ENUM</type>
</sortType>
<supported-locales>en_AU</supported-locales>
<userId>
<deprecated>true</deprecated>
<search-param>optional</search-param>
<search-style>eq</search-style>
<since>1.0</since>
<type>LONG</type>
</userId>
<userIds>
<deprecated>false</deprecated>
<search-param>optional</search-param>
<search-style>in</search-style>
<since>1.5</since>
</userIds>
<version>1.13</version>
<zipcode>
<deprecated>false</deprecated>
<localized-label>Postcode</localized-label>
<search-param>unsupported</search-param>
<since>1.0</since>
<type>STRING</type>
</zipcode>
</value>
</httpwwwebayclassifiedsgroupcomschemaadv1_ads-search-options>