Occasionally, you will discover that the document created by the ODT exporter cannot be opened by your favorite application. One of the common reasons for this is that the .odt file is corrupt. In such cases, you may want to validate the document against the OpenDocument RELAX NG Compact Syntax (RNC) schema.
For de-compressing the .odt file1: see File Archives. For general help with validation (and schema-sensitive editing) of XML files: see Introduction.
If you have ready access to OpenDocument .rnc files and the needed
schema-locating rules in a single folder, you can customize the variable
org-odt-schema-dir to point to that directory. The ODT exporter
will take care of updating the
rng-schema-locating-files for you.
 .odt files are nothing but ‘zip’ archives