Key share is null error (gg2020)

[tmpfs]

Intermittent error when signing:

Uncaught (in promise) TypeError: keyShare is null
    signMessage http://localhost:8080/index.js:87202
    step http://localhost:8080/index.js:87184
    verb http://localhost:8080/index.js:87165
    __awaiter http://localhost:8080/index.js:87159
    __awaiter http://localhost:8080/index.js:87155
    signMessage http://localhost:8080/index.js:87193
    sign http://localhost:8080/index.js:86625
    step http://localhost:8080/index.js:86605
    verb http://localhost:8080/index.js:86586
    __awaiter http://localhost:8080/index.js:86580
    __awaiter http://localhost:8080/index.js:86576
    sign http://localhost:8080/index.js:86613
    onSignMessage http://localhost:8080/index.js:86355
    step http://localhost:8080/index.js:86253
    verb http://localhost:8080/index.js:86234
    fulfilled http://localhost:8080/index.js:86225
    promise callback*step http://localhost:8080/index.js:86227
    __awaiter http://localhost:8080/index.js:86228
    __awaiter http://localhost:8080/index.js:86224
    onSignMessage http://localhost:8080/index.js:86346
    onceWrapper http://localhost:8080/index.js:31158
    emit http://localhost:8080/index.js:31068
    WebSocketClient http://localhost:8080/index.js:85368
    step http://localhost:8080/index.js:85296
    verb http://localhost:8080/index.js:85277
    __awaiter http://localhost:8080/index.js:85271
    __awaiter http://localhost:8080/index.js:85267
    onmessage http://localhost:8080/index.js:85349
index.js:87202:42