Thanks support team, But I am afraid that i won't be able to share the solution due to company policy.
However I am attaching one of the proj file and prop file here, error are related with this.
Also, I have noticed that, in the prop file we are using the <RanorexVersion>6</RanorexVersion>, if I delete this line then it works fine and able to load the solution.
Test.RanorexProjectSettings.props
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="
http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<OutputPath>$(ProjectDir)..\..\bin\$(Platform)\$(Configuration)\</OutputPath>
<ReferencePath>$(ProjectDir)..\..\bin\$(Platform)\$(Configuration)\SmokeTest;$(ProjectDir)..\..\bin\$(Platform)\$(Configuration)\SmokeTest\Radon-FW;$(ProjectDir)..\..\bin\$(Platform)\$(Configuration)\SmokeTest\Radon-FW\Ranorex</ReferencePath>
<Configuration Condition=" '$(Configuration)' == '' "/>
<Platform Condition=" '$(Platform)' == '' "/>
<RanorexVersion>6</RanorexVersion>
<TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
<CheckForOverflowUnderflow>True</CheckForOverflowUnderflow>
<CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
<DebugSymbols>true</DebugSymbols>
<DebugType>Full</DebugType>
<DefineConstants>DEBUG;TRACE</DefineConstants>
<Optimize>False</Optimize>
<PlatformTarget>x64</PlatformTarget>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
<CheckForOverflowUnderflow>False</CheckForOverflowUnderflow>
<CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
<DebugSymbols>False</DebugSymbols>
<DebugType>None</DebugType>
<DefineConstants>TRACE</DefineConstants>
<Optimize>True</Optimize>
<PlatformTarget>x64</PlatformTarget>
</PropertyGroup>
<ItemGroup>
<Reference Include="Ranorex.Core, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.ChromeWeb, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Flex, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Java, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Mobile, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.MozillaWeb, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Msaa, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Office, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Qt, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.RawText, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Sap, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Web, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Win32, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.WinForms, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Wpf, Version=$(RanorexVersion)" />
<Reference Include="System" />
<Reference Include="System.Data" />
<Reference Include="System.Drawing" />
<Reference Include="System.Windows.Forms" />
<Reference Include="System.Xml" />
</ItemGroup>
</Project>
================================
Test.BusinessLayer.BusinessLayer.csproj
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="
http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<ProjectGuid>{E1F46EEC-4BED-47C7-842A-6DAAAFE71BE6}</ProjectGuid>
<OutputType>Library</OutputType>
<RootNamespace>Test.BusinessLayer</RootNamespace>
<AssemblyName>Test.BusinessLayer</AssemblyName>
<TargetFrameworkProfile />
<TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
<AllowUnsafeBlocks>False</AllowUnsafeBlocks>
<NoStdLib>False</NoStdLib>
<DebugType>None</DebugType>
<WarningLevel>4</WarningLevel>
<TreatWarningsAsErrors>false</TreatWarningsAsErrors>
<DebugSymbols>false</DebugSymbols>
<SccProjectName>SAK</SccProjectName>
<SccLocalPath>SAK</SccLocalPath>
<SccAuxPath>SAK</SccAuxPath>
<SccProvider>SAK</SccProvider>
</PropertyGroup>
<PropertyGroup Condition=" '$(Platform)' == 'x64' ">
<PlatformTarget>x64</PlatformTarget>
<PostSharpDisabledMessages>PS0131</PostSharpDisabledMessages>
<RegisterForComInterop>False</RegisterForComInterop>
<GenerateSerializationAssemblies>Auto</GenerateSerializationAssemblies>
<BaseAddress>4194304</BaseAddress>
<FileAlignment>4096</FileAlignment>
</PropertyGroup>
<PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
<Optimize>False</Optimize>
<CheckForOverflowUnderflow>False</CheckForOverflowUnderflow>
</PropertyGroup>
<Import Project="$(ProjectDir)..\..\_Globals\Test.RanorexProjectSettings.props" />
<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
<DocumentationFile>..\..\bin\x64\Debug\Test.BusinessLayer.XML</DocumentationFile>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
<DocumentationFile>..\..\bin\x64\Release\Test.BusinessLayer.XML</DocumentationFile>
</PropertyGroup>
<Import Project="$(MSBuildBinPath)\Microsoft.CSharp.Targets" />
<ItemGroup>
<Reference Include="Ranorex.Core, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.ChromeWeb, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Flex, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Java, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Mobile, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.MozillaWeb, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Msaa, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Office, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Qt, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.RawText, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Sap, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Uia, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Web, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Win32, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.WinForms, Version=$(RanorexVersion)" />
<Reference Include="Ranorex.Plugin.Wpf, Version=$(RanorexVersion)" />
<Reference Include="System.Core" />
<Reference Include="System.Data" />
<Reference Include="System.Drawing" />
<Reference Include="System.Windows.Forms" />
</ItemGroup>
<ItemGroup>
<Compile Include="AssemblyInfo.cs">
<id>3ea89436-2b2e-4724-940e-f1a58065df06</id>
</Compile>
<Compile Include="SetupTearDown\StartingApplication.cs">
<id>a7ef1761-6f4d-4495-ae11-e5b177b861de</id>
</Compile>
</ItemGroup>
<Import Condition="Exists('$(MSBuildExtensionsPath)\Ranorex$(RanorexVersion)\Ranorex.MSBuild.Targets')" Project="$(MSBuildExtensionsPath)\Ranorex$(RanorexVersion)\Ranorex.MSBuild.Targets" />
<ItemGroup>
<ProjectReference Include="..\Test.UIRepository\Test.UIRepository.csproj">
<Project>{1D626D7C-632F-4E60-B0E4-BC5E601809E5}</Project>
<Name>Test.UIRepository</Name>
</ProjectReference>
<ProjectReference Include="..\Test.UtilLayer\Test.UtilLayer.csproj">
<Project>{80082F17-F332-42CC-A086-AE37BC62F356}</Project>
<Name>Test.UtilLayer</Name>
<Private>False</Private>
</ProjectReference>
</ItemGroup>
</Project>