LSP Signature Help Request on the first line raise exception

[mayanje]

Description
In the TypeCobol Plugin Invoking a signature help on the first line of a Document raise an unexpected exception from the LSP server.

How to reproduce

• Open a document in the TypeCobol RDz plugin

• Enter an empty first line in the document

• Put the caret in the first line of the document

• Perform Ctrl+Shift+Space action
  The following popup will be raised.