No output, `org-ql: No headings in buffer`, and `elgantt--header-line-formatter wrong type argument characterp nil`

[anoduck]

Recommended this project on Reddit to build a direly needed timeline, and not having any luck right now. I am using the test file, test.org, and my configuration is posted below:

;; configured time stamps to display
(setq elgantt-agenda-files "~/to/the/test/file/dir")
(setq elgantt-header-type 'outline)
(setq elgantt-timestamps-to-display `(
				      scheduled
				      deadline
				      timestamp-ia
				      timestamp-range-ia
				      )
      elgantt-header-type 'outline
      elgantt-insert-blank-line-between-top-level-header nil
      elgantt-startup-folded nil
      elgantt-draw-overarching-headers t
      elgantt-show-header-depth t
      elgantt-hide-number-line t
      elgantt-insert-header-even-if-no-timestamp t
      elgantt-skip-archives t
      elgantt-scroll-to-current-month-at-startup nil)
(setq elgantt-start-date "2019-01-01")

With the above configuration and the test file, I am receiving numerous errors attempting to get elgantt to render. I am most suspicious of the errors received from org-ql, which is the most probable culprit IMHO. First it output org-ql: Not an org file then it moved to org-ql: No headings in buffer. So, regardless of configuration changes, it has maintained a steady stream of errors.

Once I covered all my bases, setting questionable settings to what is listed as working in the repository, then came along the header-line-formatter error. The full output is:

Error during redisplay: (eval (elgantt--header-line-formatter)) signaled (wrong-type-argument characterp nil)

Which might be related to org-ql? I dunno. Just shooting in the dark, hoping I hit something meaningful.