当我运行以下命令时：
serverless sam export --output ./sam-template.yml
我收到以下错误。我正在使用无服务器v.1.30.3和节点v10.9，我不太确定从哪里开始此错误消息，因为在线搜索没有产生任何类似的问题/修复。任何指针将不胜感激！
Type Error ---------------------------------------------
Cannot read property 'charAt' of undefined
For debugging logs, run again after setting the "SLS_DEBUG=*" environment variable.
Stack Trace --------------------------------------------
TypeError: Cannot read property 'charAt' of undefined
at StreamEventConverter.convertEvent (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/lib/events/StreamEventConverter.js:29:33)
at Object.keys.forEach (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/lib/FunctionConverter.js:101:49)
at Array.forEach (<anonymous>)
at serverlessFunction.events.forEach (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/lib/FunctionConverter.js:95:33)
at Array.forEach (<anonymous>)
at FunctionConverter.serverlessFunctionToSam (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/lib/FunctionConverter.js:89:33)
at allFunctions.forEach (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/lib/SamGenerator.js:119:32)
at Array.forEach (<anonymous>)
at SamGenerator.readFunctions (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/lib/SamGenerator.js:109:20)
at SamGenerator.generate (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/lib/SamGenerator.js:58:10)
at BbPromise (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/index.js:206:46)
at SamPlugin.exportSam (/Users/marian/goop/src/github.com/goop/service-wms/node_modules/serverless-sam/index.js:203:12)
From previous event:
at PluginManager.invoke (/Users/marian/.nvm/versions/node/v10.9.0/lib/node_modules/serverless/lib/classes/PluginManager.js:390:22)
at PluginManager.run (/Users/marian/.nvm/versions/node/v10.9.0/lib/node_modules/serverless/lib/classes/PluginManager.js:421:17)
at variables.populateService.then.then (/Users/marian/.nvm/versions/node/v10.9.0/lib/node_modules/serverless/lib/Serverless.js:157:33)
at runCallback (timers.js:693:18)
at tryOnImmediate (timers.js:664:5)
at processImmediate (timers.js:646:5)
at process.topLevelDomainCallback (domain.js:121:23)
From previous event:
at Serverless.run (/Users/marian/.nvm/versions/node/v10.9.0/lib/node_modules/serverless/lib/Serverless.js:144:8)
at serverless.init.then (/Users/marian/.nvm/versions/node/v10.9.0/lib/node_modules/serverless/bin/serverless:43:50)