Jenkins Blue Ocean not loading after initial install on existing Jenkins instance

Question

I just installed Blue Ocean on an existing Jenkins instance that I have been using for years. The landing page is not loading, and I'm getting the following error, which I have been unsuccessful in finding an answer to on SO or otherwise googling. I'm on Jenkins build 2.107.3, Blue Ocean 1.6.1.

I was able to create a new pipeline successfully, but when I go back to this page, it never finishes loading.

Has anyone encountered this error, or has advice on how to go about debugging it?

blueocean-core-js.js:57883 Error fetching page TypeError: Cannot read property 'self' of undefined at ActivityService.bunkerKey (blueocean-core-js.js:57207) at ActivityService.setItem (blueocean-core-js.js:57250) at executeAction (blueocean-core-js.js:40729) at ActivityService.res (blueocean-core-js.js:40701) at PipelineService._this.bunkerMapper (blueocean-core-js.js:58214) at PipelineService.setItem (blueocean-core-js.js:57249) at executeAction (blueocean-core-js.js:40729) at PipelineService.res (blueocean-core-js.js:40701) at blueocean-core-js.js:57268 at Array.map (<anonymous>) at PipelineService.setItems (blueocean-core-js.js:57267) at blueocean-core-js.js:57867 at executeAction (blueocean-core-js.js:40729) at res (blueocean-core-js.js:40701)