I ve enabled NLog internal logging to figure out an issue where our logs suddenly stop sometimes. Might be unrelated to the issue I m trying to figure out but I ve gotten this Exception for one of the targets (FileTarget logging with ConcurrentWrites = true, wrapped by AsyncTargetWrapper). This is a file where a couple of running applications should be able to write to. Before this error this file is already created and written to I m currently running NLog version 5.2.8 on all applications The error is: 2024-07-22 12:35:33.2512 Debug EventLogTarget([unnamed]): Refresh EventLog Source Company.WCF.Client.Console - Client and Log Application 2024-07-22 12:35:33.2512 Debug FileTarget([unnamed]): Preparing for new file: C:ProgramDataCompanyLogsAllExceptions.txt 2024-07-22 12:35:33.2512 Debug FileTarget([unnamed]): Creating file appender: C:ProgramDataCompanyLogsAllExceptions.txt 2024-07-22 12:35:33.2512 Warn FileTarget([unnamed]): Failed to create file appender: C:ProgramDataCompanyLogsAllExceptions.txt Exception: System.UnauthorizedAccessException: Access to the path C:ProgramDataCompanyLogsAllExceptions.txt is denied. 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, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost) at System.IO.FileStream..ctor(String path, FileMode mode, FileSystemRights rights, FileShare share, Int32 bufferSize, FileOptions options) at NLog.Internal.FileAppenders.WindowsMultiProcessFileAppender.CreateAppendOnlyFile(String fileName) at NLog.Internal.FileAppenders.WindowsMultiProcessFileAppender..ctor(String fileName, ICreateFileParameters parameters) at NLog.Internal.FileAppenders.WindowsMultiProcessFileAppender.Factory.NLog.Internal.FileAppenders.IFileAppenderFactory.Open(String fileName, ICreateFileParameters parameters) at NLog.Internal.FileAppenders.FileAppenderCache.CreateAppender(String fileName, Int32 freeSpot) Could I get an explanation on why this could be triggered? This seems to have happened while the applications were running on my development machine, without any intervention at that timestamp