harmonyos预览功能报错

在使用DevEco Studio写页面，进行预览的时候报错：

[Compile Result] [webpack-cli] SyntaxError: Unexpected end of JSON input
[Compile Result]     at JSON.parse (<anonymous>)
[Compile Result]     at updateCachedSourceMaps (/Users/wmding/Tools/Huawei/Sdk/openharmony/9/ets/build-tools/ets-loader/lib/gen_abc_plugin.js:1:11188)
[Compile Result]     at handleFullModuleFiles (/Users/wmding/Tools/Huawei/Sdk/openharmony/9/ets/build-tools/ets-loader/lib/gen_abc_plugin.js:1:14163)
[Compile Result]     at GenAbcPlugin.handleFinishModules (/Users/wmding/Tools/Huawei/Sdk/openharmony/9/ets/build-tools/ets-loader/lib/gen_abc_plugin.js:2:3272)
[Compile Result]     at Hook.eval [as callAsync] (eval at create (/Users/wmding/Tools/Huawei/Sdk/openharmony/9/ets/build-tools/ets-loader/node_modules/webpack/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:40:1)
[Compile Result]     at Hook.CALL_ASYNC_DELEGATE [as _callAsync] (/Users/wmding/Tools/Huawei/Sdk/openharmony/9/ets/build-tools/ets-loader/node_modules/webpack/node_modules/tapable/lib/Hook.js:18:14)
[Compile Result]     at Compilation.finish (/Users/wmding/Tools/Huawei/Sdk/openharmony/9/ets/build-tools/ets-loader/node_modules/webpack/lib/Compilation.js:2714:28)
[Compile Result]     at /Users/wmding/Tools/Huawei/Sdk/openharmony/9/ets/build-tools/ets-loader/node_modules/webpack/lib/Compiler.js:1182:19
[Compile Result]     at processTicksAndRejections (node:internal/process/task_queues:78:11)
[Compile Result] Compile error occurred. Fix it based on the above message.

问题分析：

明明上一分钟还在好好的写代码，预览功能还能正常使用，然后刷新预览功能之后就报错了。无论如何修改代码或者还原代码都报错。

分析排查：

1.打开另一个工程，页面可以预览，说明跟开发工具应该没有关系

2.检查代码是否有修改，是否影响

3.仔细查看报错日志，写的的updateCachedSourceMaps，有显示Cache，说明和缓存有一定关系，对项目进行clean、rebuild，不管用。

4.预览功能是否有缓存呢？对，entry下的.preview文件就是项目预览页面的缓存等内容

解决问题

删除entry下的.preview文件，重新预览，现在可以了