There are several different settings that will prevent content in a document from being changed by a merge session: 

• Confirm the content is assigned to a variable link.

To determine this, you can set the document to show DesignMerge visual indicators for variable links, or you can use the DesignMerge panel to confirm the content has been tagged as a variable. It may also be helpful to run a Variable Link Report merge session. A Variable Link Report will list all of the variable links that are in the document, providing information about their settings and current status, which will indicate whether a variable link is encountering an error and if a variable link is locked, as described next.

• Confirm this variable link assignment is not locked.

To confirm this, select the variable link in the document and then open the DesignMerge panel and look at the Lock check box on the DesignMerge panel. Locking a variable link assignment indicates that this one variable link should not be merged or changed by a merge session. 

• Confirm the variable link is not locked. 

To confirm this, open the Variable Links dialog, select the variable link by its name on the left, and look at the Lock check box on the right side of the dialog. Locking a Variable Link indicates that all assignments of this variable link in a document should not be merged or changed by a merge session. 

• Confirm the variable link is not ignored when empty.

To confirm this, open the Variable Links dialog, select the variable link by its name on the left, and look at the Empty Link setting on the right side of the dialog. If Ignore is selected, DesignMerge will not merge or change this variable link when a record does not have any data for it.

• Confirm your DesignMerge preferences.

For example, confirm All is selected for the Merge Options. Also, review how you would prefer a merge session handle various error conditions. For example, consider whether you would prefer DesignMerge Prompt for Missing or Damaged Assets, or instead would prefer this condition be treated automatically as a merge error.  

For more information, see Tutorial #1 (The Basics) in DesignMerge Documentation. This tutorial provides step-by-step instructions and helpful information for setting up variable links, placing variable links in a document, showing visual indicators for variable links in a document, using the DesignMerge panel, and running a Variable Link Report. DesignMerge Documentation also provides more information about DesignMerge Preferences.