Error: Unsolved Text

There are two "standard options"

1: Open the panel "Insets" - View->Panel. The inset ought to be there and a click ought to bring  you to the place of insertion.

2: Another option is to generate a list of references and choose "Unresolved Text Insets"

If you click the option for "Generate Hypertext Links" you ought to get a link directly to the place of insertion,

Open the document and choose Edit > Find/Change. Set the Find to this:

Double-click on the unresolved text inset and it will tell you the path to the text inset.