我正在尝试在ASP.net Core中安装一个软件包，我正在使用完整的.net框架，但我收到一个错误，我正在尝试安装的软件包是Dropnet，它不是第一个显示此消息的时间，这也发生在其他时间，我得到的消息是：
error: Package dependencies must specify a version range.
这是我的project.json文件：
{
"dependencies": {
"AWSSDK": "2.3.55.2",
"AWSSDK.DynamoDBv2": "3.3.0.2",
"Dropbox.Api": "3.6.0",
"DropNet": "1.10.23",
"EntityFramework": "6.1.3",
"Microsoft.ApplicationInsights.AspNetCore": "1.0.0",
"Microsoft.AspNet.Mvc": "5.2.3",
"Microsoft.AspNetCore.Diagnostics": "1.0.0",
"Microsoft.AspNetCore.Mvc": "1.0.0",
"Microsoft.AspNetCore.Razor.Tools": {
"version": "1.0.0-preview2-final",
"type": "build"
},
"Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
"Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
"Microsoft.AspNetCore.StaticFiles": "1.0.0",
"Microsoft.Extensions.Caching.Memory": "",
//"Microsoft.EntityFrameworkCore": "1.0.1",
//"Microsoft.EntityFrameworkCore.SqlServer": "1.0.1",
"Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
"Microsoft.Extensions.Configuration.Json": "1.0.0",
"Microsoft.Extensions.Logging": "1.0.0",
"Microsoft.Extensions.Logging.Console": "1.0.0",
"Microsoft.Extensions.Logging.Debug": "1.0.0",
"Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0",
"Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0",
"MongoDB.Bson": "2.3.0",
"MongoDB.Driver": "2.3.0"
},
"tools": {
"BundlerMinifier.Core": "2.0.238",
"Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final",
"Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
},
"frameworks": {
"net452": {
"dependencies": {
"SharedClasses": {
"target": "project"
}
}
}
},
"buildOptions": {
"emitEntryPoint": true,
"preserveCompilationContext": true
},
"publishOptions": {
"include": [
"wwwroot",
"Views",
"Areas/**/Views",
"appsettings.json",
"web.config"
]
},
"scripts": {
"prepublish": [ "bower install", "dotnet bundle" ],
"postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
}
}
我该如何解决这个问题？