I have already spent hours on this trying to figure it out. It is driving me nuts. 

The ENTIRE site works perfectly EXCEPT for the Media Tree, it just sits there loading. All the media is still in tact because the front end of the site is still calling all of the media and displaying correctly. 

I have already checked all the config files to make sure they are all updated. 

I get an error (when using Inspector) on the Media page. 

/umbraco/webservices/TreeDataService.ashx?rnd=0697997014504d769d10034385a0d63f&id=-1&treeType=media&contextMenu=true&isDialog=false&rnd2=24.1

Win32Exception (0x80004005): The wait operation timed out]

[SqlException (0x80131904): Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.]
   System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +1754082
   System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) +5295874
   System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +242
   System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +1682
   System.Data.SqlClient.SqlDataReader.TryConsumeMetaData() +59
   System.Data.SqlClient.SqlDataReader.get_MetaData() +90
   System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +365
   System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite) +1325
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) +175
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +53
   System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +134
   System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +41
   System.Data.Common.DbCommand.ExecuteReader(CommandBehavior behavior) +10
   StackExchange.Profiling.Data.ProfiledDbCommand.ExecuteDbDataReader(CommandBehavior behavior) +68
   System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader() +12
   Umbraco.Core.Persistence.<>c__DisplayClass4.<ExecuteReaderWithRetry>b__3() +99
   Umbraco.Core.Persistence.FaultHandling.RetryPolicy.ExecuteAction(Func`1 func) +170
   Umbraco.Core.Persistence.PetaPocoCommandExtensions.ExecuteReaderWithRetry(IDbCommand command, RetryPolicy cmdRetryPolicy, RetryPolicy conRetryPolicy) +118
   Umbraco.Core.Persistence.PetaPocoCommandExtensions.ExecuteReaderWithRetry(IDbCommand command, RetryPolicy retryPolicy) +52
   Umbraco.Core.Persistence.PetaPocoCommandExtensions.ExecuteReaderWithRetry(IDbCommand command) +49
   Umbraco.Core.Persistence.<Query>d__1c`1.MoveNext() +169
   System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) +381
   System.Linq.Enumerable.ToList(IEnumerable`1 source) +58
   Umbraco.Core.Persistence.Database.Fetch(Func`3 cb, Sql sql) +126
   Umbraco.Core.Persistence.Repositories.EntityRepository.GetByQuery(IQuery`1 query, Guid objectTypeId) +524
   Umbraco.Core.Services.EntityService.GetChildren(Int32 parentId, UmbracoObjectTypes umbracoObjectType) +351
   umbraco.cms.presentation.Trees.BaseMediaTree.Render(XmlTree& tree) +511
   umbraco.loadMedia.Render(XmlTree& tree) +19
   umbraco.presentation.webservices.TreeDataService.LoadTree(TreeRequestParams treeParams) +76
   umbraco.presentation.webservices.TreeDataService.GetXmlTree() +156
   umbraco.presentation.webservices.TreeDataService.ProcessRequest(HttpContext context) +123
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +341
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69