XML Warning: "Duplicate unique value [...] declared for identify constraint "..." of element "..""
Issue description
This XML warning occurs when two provisions in your document have the same underlying ID as each other.
This should not typically occur (as Lawmaker is set up to try and avoid this), but sometimes if you copy and paste provisions around this issue can occur.
Generally, we don’t encourage users to try and fix XML Warnings themselves (as opposed to document warnings), but this issue is relatively simple to fix.

Example of this XML warning
To fix this issue:
1. Renumber your document
In the first instance, you may be able to fix this issue by renumbering your document (or the affected Quoted Structure if relevant).
Before renumbering the document, check that there are no parts of your document that you do not want to renumber (e.g., if you have manually edited numbers, “3A” or suchlike, and you want to keep this), and that are not locked.
If there are, lock them first. See Locking and unlocking numbers . This will prevent them from being renumbered.
You may want to also lock the number after the number you have edited (else it will follow on from the previous, edited number - e.g., “3A”, “3B”, “3C” etc.)
To renumber your document:
Place your cursor in the location of the error
Press Alt+N
Select to renumber the whole document or Quoted Structure as relevant.
This may resolve the issue (as the affected should get updated IDs, which will be unique).
Edit the ID
If renumbering the document does not work, or you do not want to renumber your document for whatever reason, you can manually edit the affected ID to make it unique and get rid of this issue.
Please try the following:
In the error message, identify the ‘identity constraint’ affected (either “eID” or “GUID”). This should be included in the text of the message, e.g.:
Duplicate unique value [_38df5533-653a-4285-86f6-0f5178fcd5ad] declared for identity constraint "GUID-act" of element "act".Click on the error message to highlight the affected provision.
Go to Attributes (the 'tag' icon in the right hand panel).
You should see the same ID as is mentioned in the error message, e.g.:

Click in this field and make a change to the ID (e.g., add "_oc2” at the end) and click Accept.
This should resolve the issue as the provision will now have a unique ID.
References
If you have references in your document to the affected provision, you should check those references after you have implemented the fixes above.
You may need to re-create the references in question., as the IDs that you have recreated are used to identify and link to the provisions being referenced.
See References for further info.
If you struggle with the above, please raise a ticket with Lawmaker support and specify that you are encountering XML warnings relating to duplicate IDs.