Salesforce CPQ error 'Unknown Field' on Quote Document view

This issue occurs when API values are pasted in to the HTML content for use as a merge field due to lingering HTML tags. Below is an example of what may occur when copying and pasting a field's API name:

1. Merge Field format from Quote object begin like this: {!quote. }
2. Copy field API name and paste brings HTML code: {!quote.<p>FieldAPIName__c< /p>}
3. Prints on generated document as follows: Unknown field: <p>FieldAPIName__c< /p>

The HTML tags cause the field API name to no longer be correct because additional characters were introduced in the merge field. To resolve this error:

1. Navigate to the Template Content in which the error is being observed.
2. Click Edit to edit the content.
3. In the Markup editor, take note of the merge field that is not merging properly.
4. Highlight the entire merge field, including the braces at the beginning and end.
5. Cut this text using the keyboard shortcut Ctrl/Cmd+X or the 'Cut' scissors-shaped button in the formatting bar.
6. Click the "Paste as plain text" button (clipboard and a 'T' in a box).
7. In the popup window, paste in the merge field using Ctrl/Cmd+V, then click OK.