ClickOnce Prerequisites: where is SQL Server Express 2014 LocalDB?

The solution for Localdb2017

Copy the SqlLocalDB2017 folder into the proper place e.g.: c:\Program Files (x86)\Microsoft SDKs\ClickOnce Bootstrapper\Packages and restart Visual Studio.

As I posted on the MSDN forums I created my own package as an official version doesn't exist. The package is basically just a copy of the SqlLocalDB2012 package updated to point to the new version of msi files to download.

I've put all the files for the boostrapper package on GitHub so people don't have to create the files themselves. There's two versions, one for the original release and one for the SP1 release. Following are the steps to create the original release version yourself:

1. Create a folder SqlLocalDB2014

2. Create an xml file in the folder called product.xml with the following contents:

   <?xml version="1.0" encoding="utf-8"?>
   <Product xmlns="http://schemas.microsoft.com/developer/2004/01/bootstrapper" ProductCode="Microsoft.SqlServer.SqlLocalDB.12.0">
     <InstallChecks>
       <FileCheck
         Property="sqllocaldbVersion"
         FileName="sqlservr.exe"
         SearchPath="Microsoft SQL Server\120\LocalDB\Binn"
         SpecialFolder="ProgramFilesFolder"
       />
     </InstallChecks>
   
     <PackageFiles CopyAllPackageFiles="false">
       <PackageFile
         Name="x86\sqllocaldb.msi"
         HomeSite="sqllocaldb_32"
         PublicKey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
       />
       <PackageFile
         Name="x64\sqllocaldb.msi"
         HomeSite="sqllocaldb_64"
         PublicKey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
       />
     </PackageFiles>
   
     <Commands Reboot="Defer">
       <Command PackageFile="x86\sqllocaldb.msi" Arguments="IACCEPTSQLLOCALDBLICENSETERMS=YES" EstimatedInstallSeconds="90">
         <InstallConditions>
           <FailIf Property="VersionNT" Compare="ValueNotExists" String="InvalidPlatformOS" />
           <FailIf Property="VersionNT" Compare="VersionLessThan" Value="6.0.1" String="InvalidPlatformOS" />
           <FailIf Property="AdminUser" Compare="ValueEqualTo" Value="false" String="AdminRequired" />
           <BypassIf Property="ProcessorArchitecture" Compare="ValueNotEqualTo" Value="Intel" />
           <BypassIf Property="sqllocaldbVersion" Compare="VersionGreaterThanOrEqualTo" Value="2014.120.2000.8" />
         </InstallConditions>
         <ExitCodes>
           <ExitCode Value="0" Result="Success" />
           <ExitCode Value="1641" Result="SuccessReboot" />
           <ExitCode Value="3010" Result="SuccessReboot" />
           <DefaultExitCode Result="Fail" String="GeneralFailure" FormatMessageFromSystem="true" />
         </ExitCodes>
       </Command>
       <Command PackageFile="x64\sqllocaldb.msi" Arguments="IACCEPTSQLLOCALDBLICENSETERMS=YES" EstimatedInstallSeconds="90">
         <InstallConditions>
           <BypassIf Property="ProcessorArchitecture" Compare="ValueNotEqualTo" Value="amd64" />
           <BypassIf Property="sqllocaldbVersion" Compare="VersionGreaterThanOrEqualTo" Value="2014.120.2000.8" />
         </InstallConditions>
         <ExitCodes>
           <ExitCode Value="0" Result="Success" />
           <ExitCode Value="1641" Result="SuccessReboot" />
           <ExitCode Value="3010" Result="SuccessReboot" />
           <DefaultExitCode Result="Fail" String="GeneralFailure" FormatMessageFromSystem="true" />
         </ExitCodes>
       </Command>
     </Commands>
   </Product>
   

3. Within the folder create another folder called en and create another xml file called package.xml

    <?xml version="1.0" encoding="utf-8"?>
    <Package Name="DisplayName" LicenseAgreement="Eula.txt" Culture="Culture" xmlns="http://schemas.microsoft.com/developer/2004/01/bootstrapper">
      <PackageFiles>
        <PackageFile Name="Eula.txt" />
      </PackageFiles>
      <Strings>
        <String Name="Culture">en</String>
        <String Name="DisplayName">SQL Server 2014 Express LocalDB</String>
        <String Name="sqllocaldb_32">http://download.microsoft.com/download/E/A/E/EAE6F7FC-767A-4038-A954-49B8B05D04EB/LocalDB%2032BIT/SqlLocalDB.msi</String>
        <String Name="sqllocaldb_64">http://download.microsoft.com/download/E/A/E/EAE6F7FC-767A-4038-A954-49B8B05D04EB/LocalDB%2064BIT/SqlLocalDB.msi</String>
        <String Name="AdminRequired">You do not have the permissions required to install SQL Server 2014 Express LocalDB. Please contact your administrator.</String>
        <String Name="GeneralFailure">An error occurred attempting to install SQL Server 2014 Express LocalDB.</String>
        <String Name="InvalidPlatformOS">The current operating system version does not support SQL Server 2014 Express LocalDB.</String>
        <String Name="InvalidPlatformOSServicePack">The current operating system does not meet Service Pack level requirements for SQL Server 2014 Express LocalDB. Install the most recent Service Pack from the Microsoft download center at http://www.microsoft.com/downloads before continuing setup.</String>
      </Strings>
    </Package>
   

4. Copy the C:\Program Files\Microsoft SQL Server\120\License Terms\License_SqlLocalDB_1033.txt file into the en folder and rename it to eula.txt.

5. To install the package copy the folder SqlLocalDB2014 to where your other bootstrapper packages are located e.g. C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A\Bootstrapper\Packages
6. You should now be able to use the package from Visual Studio, however if you wish to have the component installed from the same location as your application then you'll need to download the two sqllocaldb.msi files specified in the package.xml file and put them in x86 and x64 folders inside the SqlLocalDb2014 folder.
7. Lastly, this package is only for English but you may support multiple languages by adding folders for each language with package.xml and eula.txt files.

I'm having exactly the same problem as well. I found one potential answer at the MSDN forum and it seems to work for me.

To summarize the answer from the link: You have to create a "bootstrapper" for LocalDB 2014. This is just a folder in your "Microsoft SDKs directory" containing some specific xml files with keys/meta-data and an eula text file. The answer in the link provides the content for these xml files. After restarting visual studio, "Sql Express 2014 LocalDB" will appear along with all the other prerequisites and can be added to ClickOnce dependencies.