鸿蒙编译错误，这是什么原因空白项目

 The @Prop property 'midButton' cannot be an optional parameter.  
WARN: ArkTS:WARN File: E:/www_app/qf/unpackage/release/qfcloud.qfjsjt.com/oh_modules/.ohpm/@dcloudio+uni-app-runtime@idazlhvgikh3aw++r+ncdsd8lhisx+iuufxvzpgrtyy=/oh_modules/@dcloudio/uni-app-runtime/src/main/ets/uni-mp-sdk/components/TabBar.ets:204:21  
 The regular property 'item!' cannot be assigned to the @ObjectLink property 'item'.  

> hvigor Finished :entry:default@CompileArkTS... after 9 s 385 ms   
> hvigor Finished :entry:default@GeneratePkgModuleJson... after 3 ms   
> hvigor WARN: Bytecode HARs [@dcloudio/uni-app-runtime, @uni_modules/hmr-for-uni-app] to integrate are not obfuscated and will not be obfuscated later.  
> hvigor WARN: If obfuscation is needed, enable obfuscation settings in this build process; failing to do so may prevent future obfuscation.   
               Properly configure obfuscation rules to avoid runtime issues.  
> hvigor Finished :entry:default@PackageHap... after 526 ms   
> hvigor ERROR: Failed :entry:default@SignHap...   
> hvigor ERROR: Signing material error  
     Detail: Signing failed. Reconfigure the signature or clear the E:\www_app\qf\unpackage\release\qfcloud.xxx.com folder and perform signing again.  
     at E:\www_app\qf\unpackage\release\qfcloud.xxx.com\build-profile.json5  
> hvigor ERROR: BUILD FAILED in 14 s 317 ms   
21:37:55.006 安装包制作失败