ConstThrown by configure when Configuration#workerURI or Configuration#wasmURI is neither falsy, a string, nor a function. A function is not called at that point, so what it returns is not validated here: one returning something other than a string fails later and quietly, when loading the worker throws and the codecs fall back to the main thread. A falsy value keeps meaning "no worker" and "no WebAssembly module", which is how the entry points excluding them unset their URI.
Invalid URI error