Home >Online Product Documentation >Table of Contents >Troubleshooting FOP Errors < Previous| Next > Troubleshooting FOP Errors If the transformation works well, but the FOP generates an error, obtain a copy of RenderX's Unofficial DTD for XSL Formatting Objects. You can find this at http://www.renderx.com. Although this DTD is not official (it is more limited than what the W3C XSL recommendation defines), it is a helpful debugging tool. To validate the generated XML against this DTD: 1. Copy the DTD to a location such as C:\fo.dtd. 2. Include a document type declaration, such as the following, in your generated document: <!DOCTYPE fo:root SYSTEM "/fo.dtd"> 3. Turn off post-processing. 4. Apply the stylesheet. 5. Save the resulting XML document. 6. Open the saved XML document in Stylus Studio. 7. Click Validate Document . < Previous| Next >