Evaluation failed: TypeError: Cannot read properties of null (reading 'duration')

[Song0013]

Workstation:/usr/local/wsong-bbb/bbb-recorder$ node export.js "http://10.108.1.234/playback/presentation/2.3/cbd1a881d363fe1229fcd1e27bbdeccf7241168e-1693992475274" wstestbbb.webm 20 true
Error: Evaluation failed: TypeError: Cannot read properties of null (reading 'duration')
at puppeteer_evaluation_script:2:72
at ExecutionContext._evaluateInternal (/usr/local/wsong-bbb/bbb-recorder/node_modules/puppeteer/lib/ExecutionContext.js:122:13)
at processTicksAndRejections (node:internal/process/task_queues:96:5)
at async ExecutionContext.evaluate (/usr/local/wsong-bbb/bbb-recorder/node_modules/puppeteer/lib/ExecutionContext.js:48:12)
at async main (/usr/local/wsong-bbb/bbb-recorder/export.js:142:27)
-- ASYNC --
at ExecutionContext. (/usr/local/wsong-bbb/bbb-recorder/node_modules/puppeteer/lib/helper.js:111:15)
at DOMWorld.evaluate (/usr/local/wsong-bbb/bbb-recorder/node_modules/puppeteer/lib/DOMWorld.js:112:20)
-- ASYNC --
at Frame. (/usr/local/wsong-bbb/bbb-recorder/node_modules/puppeteer/lib/helper.js:111:15)
at Page.evaluate (/usr/local/wsong-bbb/bbb-recorder/node_modules/puppeteer/lib/Page.js:860:43)
at Page. (/usr/local/wsong-bbb/bbb-recorder/node_modules/puppeteer/lib/helper.js:112:23)
at main (/usr/local/wsong-bbb/bbb-recorder/export.js:142:38)