Assertion failed: "boolean expression must not be null"

Assertion failed: "boolean expression must not be null"

at Object.wrapException (http://localhost:63619/dwds/src/injected/client.js:1036:17)
at Object.assertThrow (http://localhost:63619/dwds/src/injected/client.js:1482:15)
at Object.boolConversionCheck (http://localhost:63619/dwds/src/injected/client.js:1478:11)
at http://localhost:63619/dwds/src/injected/client.js:24791:21
at _wrapJsFunctionForAsync_closure.$protected (http://localhost:63619/dwds/src/injected/client.js:3589:15)
at _wrapJsFunctionForAsync_closure.call$2 (http://localhost:63619/dwds/src/injected/client.js:11698:12)
at _awaitOnObject_closure.call$1 (http://localhost:63619/dwds/src/injected/client.js:11686:32)
at StaticClosure._rootRunUnary (http://localhost:63619/dwds/src/injected/client.js:3948:18)
at _CustomZone.runUnary$2$2 (http://localhost:63619/dwds/src/injected/client.js:13095:39)
at _Future__propagateToListeners_handleValueCallback.call$0 (http://localhost:63619/dwds/src/injected/client.js:12125:51)
at Object._Future__propagateToListeners (http://localhost:63619/dwds/src/injected/client.js:3731:93)
at _Future._completeWithValue$1 (http://localhost:63619/dwds/src/injected/client.js:11956:9)
at _AsyncAwaitCompleter.complete$1 (http://localhost:63619/dwds/src/injected/client.js:11672:14)
at Object._asyncReturn (http://localhost:63619/dwds/src/injected/client.js:3561:17)
at http://localhost:63619/dwds/src/injected/client.js:8926:24
at _wrapJsFunctionForAsync_closure.$protected (http://localhost:63619/dwds/src/injected/client.js:3589:15)
at _wrapJsFunctionForAsync_closure.call$2 (http://localhost:63619/dwds/src/injected/client.js:11698:12)
at _awaitOnObject_closure.call$1 (http://localhost:63619/dwds/src/injected/client.js:11686:32)
at StaticClosure._rootRunUnary (http://localhost:63619/dwds/src/injected/client.js:3948:18)
at _CustomZone.runUnary$2$2 (http://localhost:63619/dwds/src/injected/client.js:13095:39)
at _Future__propagateToListeners_handleValueCallback.call$0 (http://localhost:63619/dwds/src/injected/client.js:12125:51)
at Object._Future__propagateToListeners (http://localhost:63619/dwds/src/injected/client.js:3731:93)
at _Future._completeWithValue$1 (http://localhost:63619/dwds/src/injected/client.js:11956:9)
at _AsyncAwaitCompleter.complete$1 (http://localhost:63619/dwds/src/injected/client.js:11672:14)
at Object._asyncReturn (http://localhost:63619/dwds/src/injected/client.js:3561:17)
at http://localhost:63619/dwds/src/injected/client.js:25367:24
at _wrapJsFunctionForAsync_closure.$protected (http://localhost:63619/dwds/src/injected/client.js:3589:15)
at _wrapJsFunctionForAsync_closure.call$2 (http://localhost:63619/dwds/src/injected/client.js:11698:12)
at _awaitOnObject_closure.call$1 (http://localhost:63619/dwds/src/injected/client.js:11686:32)
at StaticClosure._rootRunUnary (http://localhost:63619/dwds/src/injected/client.js:3948:18)
at _CustomZone.runUnary$2$2 (http://localhost:63619/dwds/src/injected/client.js:13095:39)
at _Future__propagateToListeners_handleValueCallback.call$0 (http://localhost:63619/dwds/src/injected/client.js:12125:51)
at Object._Future__propagateToListeners (http://localhost:63619/dwds/src/injected/client.js:3731:93)
at _Future._completeWithValue$1 (http://localhost:63619/dwds/src/injected/client.js:11956:9)
at _AsyncAwaitCompleter.complete$1 (http://localhost:63619/dwds/src/injected/client.js:11672:14)
at Object._asyncReturn (http://localhost:63619/dwds/src/injected/client.js:3561:17)
at http://localhost:63619/dwds/src/injected/client.js:25344:24
at _wrapJsFunctionForAsync_closure.$protected (http://localhost:63619/dwds/src/injected/client.js:3589:15)
at _wrapJsFunctionForAsync_closure.call$2 (http://localhost:63619/dwds/src/injected/client.js:11698:12)
at _awaitOnObject_closure.call$1 (http://localhost:63619/dwds/src/injected/client.js:11686:32)
at StaticClosure._rootRunUnary (http://localhost:63619/dwds/src/injected/client.js:3948:18)
at _CustomZone.runUnary$2$2 (http://localhost:63619/dwds/src/injected/client.js:13095:39)
at _Future__propagateToListeners_handleValueCallback.call$0 (http://localhost:63619/dwds/src/injected/client.js:12125:51)
at Object._Future__propagateToListeners (http://localhost:63619/dwds/src/injected/client.js:3731:93)
at _Future._completeWithValue$1 (http://localhost:63619/dwds/src/injected/client.js:11956:9)
at _Future__asyncCompleteWithValue_closure.call$0 (http://localhost:63619/dwds/src/injected/client.js:12059:18)
at StaticClosure._rootRun (http://localhost:63619/dwds/src/injected/client.js:3933:16)
at _CustomZone.run$1$1 (http://localhost:63619/dwds/src/injected/client.js:13087:39)
at _CustomZone.runGuarded$1 (http://localhost:63619/dwds/src/injected/client.js:13030:14)
at _CustomZone_bindCallbackGuarded_closure.call$0 (http://localhost:63619/dwds/src/injected/client.js:13225:25)
at Object._microtaskLoop (http://localhost:63619/dwds/src/injected/client.js:3792:24)
at StaticClosure._startMicrotaskLoop (http://localhost:63619/dwds/src/injected/client.js:3798:11)
at _AsyncRun__initializeScheduleImmediate_internalCallback.call$1 (http://localhost:63619/dwds/src/injected/client.js:11575:9)
at invokeClosure (http://localhost:63619/dwds/src/injected/client.js:1238:26)
at MutationObserver. (http://localhost:63619/dwds/src/injected/client.js:1257:18)

Start from the stack trace in dwds/src/injected/client.js, especially boolConversionCheck and the calls through assertThrow and wrapException. Reproduce the failure at the reported localhost URL, then trace the originating operation; done means the null boolean assertion is explained and no longer occurs in the affected flow.

Written by the indexing model from the issue text.