Hey @cnusbaum,
That is a strange issue. I’m looking into it. In the meantime, could you try the following?
While the UE editor is closed, open Windows explorer and navigate to %userprofile%\AppData\Local\UnrealEngine\4.26 . Delete the cesium-request-cache.sqlite file inside that directory. Then, reopen the project.
Please let me know if that happens to resolve this.
-Alex