As the question,and chrome error:
Uncaught (in promise) ReferenceError: IDBFS is not defined
at Object.Module.mountsyncFS (qtloader.js:434)
at qtloader.js:454
at callRuntimeCallbacks (eval at completeLoadEmscriptenModule (qtloader.js:485), <anonymous>:1:11247)
at preRun (eval at completeLoadEmscriptenModule (qtloader.js:485), <anonymous>:1:11806)
at run (eval at completeLoadEmscriptenModule (qtloader.js:485), <anonymous>:1:305062)
at runCaller (eval at completeLoadEmscriptenModule (qtloader.js:485), <anonymous>:1:304366)
at removeRunDependency (eval at completeLoadEmscriptenModule (qtloader.js:485), <anonymous>:1:13554)
at receiveInstance (eval at completeLoadEmscriptenModule (qtloader.js:485), <anonymous>:1:14955)
at qtloader.js:352