Local IIS cannot connect to LocalDB - asp.net

Question

I almost hate to ask this since there seem to be piles of variations of this question, but thus far none have helped.
I am trying to stand up an old ASP.Net 2.0 app that worked fine a few years ago (different computer/environment.) I can get the default/main page to display without issues. However, all database calls fail. I can connect to "(localdb)\MSSQLLocalDB" via SSMS (either with windows auth, or the intended app credentials.) Select statements run via SSMS on all tables/views/sprocs without issue (all are thus far empty, but they exist.)
Exception
Server Error in '/' Application.
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Error occurred during LocalDB instance startup: SQL Server process failed to start.)
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Error occurred during LocalDB instance startup: SQL Server process failed to start.)
Source Error:
Line 64: SqlDataAdapter da = new SqlDataAdapter(sql, connection);
Line 65: DataSet ds = new DataSet();
Line 66: da.Fill(ds);
Source File: c:\{snip}\Page.aspx.cs Line: 66
Stack Trace:
[SqlException (0x80131904): A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 50 - Local Database Runtime error occurred. Error occurred during LocalDB instance startup: SQL Server process failed to start.
)]
System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4876207
System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194
System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, SqlConnection owningObject) +354
System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject) +90
System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart) +367
System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance) +225
System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance) +189
System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection) +185
System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) +31
System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) +431
System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) +66
System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) +499
System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) +65
System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) +117
System.Data.SqlClient.SqlConnection.Open() +122
System.Data.Common.DbDataAdapter.QuietOpen(IDbConnection connection, ConnectionState& originalState) +31
System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) +112
System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) +287
System.Data.Common.DbDataAdapter.Fill(DataSet dataSet) +94
ExportProgress.Page_Load(Object sender, EventArgs e) in c:\Users\qamain\Desktop\IDC\code\web\InstructionalDays\ExportProgress.aspx.cs:66
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
System.Web.UI.Control.OnLoad(EventArgs e) +99
System.Web.UI.Control.LoadRecursive() +50
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627
Version Information: Microsoft .NET Framework Version:2.0.50727.5420; ASP.NET Version:2.0.50727.5459
Connection String
<connectionStrings>
<add name="ConnStr" connectionString="Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=MyApp;User ID=MyUser;Password=****" providerName="System.Data.SqlClient"/>
</connectionStrings>
Environment
Admin account on Win7 Pro VM, ASP.Net 2.0, SQL (various, see image below)
Debug via VS 2015 Community
I ensured that the .Open statement is indeed getting the expected connection string.
Verified database info
C:\Users\myuser>sqllocaldb info mssqllocaldb
Name: mssqllocaldb
Version: 12.0.2000.8
Shared name:
Owner: MYVM\myuser
Auto-create: Yes
State: Running
Last start time: 2/22/2017 1:33:53 AM
Instance pipe name: np:\\.\pipe\LOCALDB#E36AA52B\tsql\query
SQL Settings via SQL Server 2016 Configuration Manager
IIS Auth settings
These specify the same "myuser" as is the owner of the SQL DB
Event Log
These are the events from a single attempt to hit the page/db. The warning is the same message/exception listed at the top of this post. The SQL error (not too helpful) is repeated all five times (and are as follows.)
Troubleshooting steps
Deleted and recreated DB
Deleted following path items,
C:\Users\myuser\AppData\Local\Microsoft\Microsoft SQL Server Local
DB\Instances
Disabled Firewall to ensure it was not the problem
Recycled/restarted app pool and web site (numerous times)
Set and loadUserProfile and setProfileEnvironment to true in this file, C:\Windows\System32\inetsrv\config\applicationHost.config as indicated here
What on earth have I missed?

Answer 1

I'll leave it to the community if this is worth keeping.
The problem is now resolved, unfortunately, I don't know exactly which step resolved the issue.
I did notice just recently that deleting and recreating the MSSQLLocalDB entry via sqllocaldb.exe dropped access to the application's DB needed (along with its tables/views/etc.) This was odd because, when I tried to recreate it, SQL complained that the db.mdf file was already in the C:\Users\myser folder. I deleted the MDF and LDF files there, and then just recreated the db (contained user, tables, views, sproc) and all is finally working.
Ugh, several days of work later. No offense taken if the community feels this post is extraneous (but perhaps the collection of troubleshooting steps might be worthwhile for others.)