I tried WebGL build with Unity 2019.1.0a14 and got this issue on Chrome (Version 73.0.3674.0 (Official Build) canary (64-bit)) and Firefox (65.0b11 (64-bit)) I'm using c# threading and I think it's related to that as it occurs at the point when I call await on async operation - - `UnityLoader.js:4 To use dlopen, you need to use Emscripten's linking support, see https://github.com/kripken/emscripten/wiki/Linking UnityLoader.js:3 Invoking error handler due to Uncaught abort("To use dlopen, you need to use Emscripten's linking support, see https://github.com/kripken/emscripten/wiki/Linking") at Error at jsStackTrace (WASM_1.1.7_1.wasm.framework.unityweb:8:22735) at stackTrace [Object.stackTrace] (WASM_1.1.7_1.wasm.framework.unityweb:8:22906) at Object.onAbort (http://localhost:9090/Build/UnityLoader.js:4:11065) at abort (WASM_1.1.7_1.wasm.framework.unityweb:8:575810) at _dlopen (WASM_1.1.7_1.wasm.framework.unityweb:8:199429) at wasm-function[74732]:132 at wasm-function[74314]:215 at wasm-function[40505]:92 at wasm-function[40504]:43 at wasm-function[75955]:16 at dynCall_iii [Object.dynCall_iii] (WASM_1.1.7_1.wasm.framework.unityweb:8:544785) at invoke_iii (WASM_1.1.7_1.wasm.framework.unityweb:8:398562) at wasm-function[40506]:110 at wasm-function[75986]:15 at dynCall_vi [Object.dynCall_vi] (WASM_1.1.7_1.wasm.framework.unityweb:8:558608) at invoke_vi (WASM_1.1.7_1.wasm.framework.unityweb:8:424977) at wasm-function[40507]:66 at wasm-function[43656]:43 at wasm-function[40436]:3 at wasm-function[75947]:13 at dynCall_ii [Object.dynCall_ii] (WASM_1.1.7_1.wasm.framework.unityweb:8:542911) at invoke_ii (WASM_1.1.7_1.wasm.framework.unityweb:8:395141) at wasm-function[50549]:179 at wasm-function[75947]:13 at dynCall_ii [Object.dynCall_ii] (WASM_1.1.7_1.wasm.framework.unityweb:8:542911) at invoke_ii (WASM_1.1.7_1.wasm.framework.unityweb:8:395141) at wasm-function[40431]:338 at wasm-function[41450]:316 at wasm-function[42594]:109 at wasm-function[29635]:48 at wasm-function[75960]:18 at dynCall_iiii [Object.dynCall_iiii] (WASM_1.1.7_1.wasm.framework.unityweb:8:546082) at invoke_iiii (WASM_1.1.7_1.wasm.framework.unityweb:8:400936) at wasm-function[42609]:621 at wasm-function[75992]:17 at dynCall_vii [Object.dynCall_vii] (WASM_1.1.7_1.wasm.framework.unityweb:8:561196) at invoke_vii (WASM_1.1.7_1.wasm.framework.unityweb:8:429558) at wasm-function[28366]:176 at wasm-function[42605]:509 at wasm-function[42298]:106 at wasm-function[42579]:66 at wasm-function[42578]:59 at wasm-function[75962]:20 at dynCall_iiiii [Object.dynCall_iiiii] (WASM_1.1.7_1.wasm.framework.unityweb:8:547076) at invoke_iiiii (WASM_1.1.7_1.wasm.framework.unityweb:8:402797) at wasm-function[42580]:672 at wasm-function[75992]:17 at dynCall_vii [Object.dynCall_vii] (WASM_1.1.7_1.wasm.framework.unityweb:8:561196) at invoke_vii (WASM_1.1.7_1.wasm.framework.unityweb:8:429558) at wasm-function[28364]:176`