I am hosted on azure and STILL getting this error even with the settings described here:

https://our.umbraco.com/Documentation/Getting-Started/Setup/Server-Setup/azure-web-apps#recommended-configuration

specifically app settings:

<add key="Umbraco.Core.LocalTempStorage" value="EnvironmentTemp" />
<add key="Umbraco.Examine.LuceneDirectoryFactory" value="Examine.LuceneEngine.Directories.SyncTempEnvDirectoryFactory, Examine" />
<add key="WEBSITE_DISABLE_OVERLAPPED_RECYCLING" value="1" />

The app does not scale out (more than one instance).. So i am confused and frustrated as to why this is still happening?

Here is the actual error:

Server Error in '/' Application. Boot failed: Umbraco cannot run. See Umbraco's log file for more details.

-> Umbraco.Core.Exceptions.BootFailedException: Boot failed.

-> System.IO.IOException: The process cannot access the file 'D:\local\Temp\UmbracoData\c5e194110ba468ba2305ef3ad38d9528\NuCache\NuCache.Content.db' because it is being used by another process. at System.IO._Error.WinIOError(Int32 errorCode, String maybeFullPath) at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITYATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost) at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options) at CSharpTest.Net.IO.TransactedCompoundFile..ctor(Options options) at CSharpTest.Net.Storage.BTreeFileStoreV2..ctor(Options options) at CSharpTest.Net.Collections.BPlusTree2.OptionsV2.CreateStorage() at CSharpTest.Net.Collections.BPlusTree2.NodeCacheBase..ctor(BPlusTreeOptions2 options) at CSharpTest.Net.Collections.BPlusTree2.NodeCacheNone..ctor(BPlusTreeOptions2 options) at CSharpTest.Net.Collections.BPlusTree2..ctor(BPlusTreeOptions`2 ioptions) at Umbraco.Web.PublishedCache.NuCache.DataSource.BTree.GetTree(String filepath, Boolean exists) in d:\a\1\s\src\Umbraco.Web\PublishedCache\NuCache\DataSource\BTree.cs:line 27 at Umbraco.Web.PublishedCache.NuCache.PublishedSnapshotService.MainDomRegister() in d:\a\1\s\src\Umbraco.Web\PublishedCache\NuCache\PublishedSnapshotService.cs:line 176 at Umbraco.Core.MainDom.Register(Action install, Action release, Int32 weight) in d:\a\1\s\src\Umbraco.Core\MainDom.cs:line 102 at Umbraco.Web.PublishedCache.NuCache.PublishedSnapshotService..ctor(PublishedSnapshotServiceOptions options, IMainDom mainDom, IRuntimeState runtime, ServiceContext serviceContext, IPublishedContentTypeFactory publishedContentTypeFactory, IdkMap idkMap, IPublishedSnapshotAccessor publishedSnapshotAccessor, IVariationContextAccessor variationContextAccessor, IProfilingLogger logger, IScopeProvider scopeProvider, IDocumentRepository documentRepository, IMediaRepository mediaRepository, IMemberRepository memberRepository, IDefaultCultureAccessor defaultCultureAccessor, IDataSource dataSource, IGlobalSettings globalSettings, IEntityXmlSerializer entitySerializer, IPublishedModelFactory publishedModelFactory, UrlSegmentProviderCollection urlSegmentProviders) in d:\a\1\s\src\Umbraco.Web\PublishedCache\NuCache\PublishedSnapshotService.cs:line 125 at DynamicMethod(Object[] )