🐛 Adding an additional main file fails to load Sandbox

[dance2die]

🐛 bug report

Description of the problem

For this Sandbox, I've added an additional file to main property within package.json file.

package.json

{
  ...
  "main": ["index.js", "useCallbackDemo.js"],
  ...
}

Doing so auto reloaded the whole page & started displaying following loading screen with following error page (without loading the sandbox).

BaseController.js:224 Uncaught TypeError: e.startsWith is not a function
at Object.t.absolute (path.js:111)
at t.default.getEntries (template.js:77)
at t.default.getDefaultOpenedFiles (template.js:95)
at c (main-module.js:29)
at Object.wa [as function] (actions.js:138)
at e.value (FunctionTree.js:98)
at executeTree.js:77
at r.executeBranchWrapper (FunctionTree.js:247)
at t (executeTree.js:13)
at n (executeTree.js:15)

And I can't seem to get it loading at this point.

How has this issue affected you? What are you trying to accomplish?

I've tried to create two main entry points and the sandbox has failed to load, thus inaccessible to the source code.

Link to sandbox

https://codesandbox.io/s/jl2qpjn795

Your Environment

Software	Name/Version
Сodesandbox	PROD-1554491263-be5b09e5c
Browser	Version 73.0.3683.103 (Official Build) (64-bit)
Windows 10	Version 1803 (OS Build 17134.648)
Ubuntu	18.10

The same error/misbehaviors occur on latest version of Windows 10 & Ubuntu 18.10

➕ Addtional Context

Following is the sandbox title, React Hooks Dependency? and or OR?.

[CompuIves]

Very good one! I made the main file resolvement more robust, the fix will be live in ~20 min.