ReadFile.cs

        public NtStatus ReadFile(string fileName, byte[] buffer, out int bytesRead, long offset, IDokanFileInfo info)
        {
            if (info.Context is Attachment att)
            {
                if (att.rawData != null)
                {
                    Console.WriteLine(att.rawData.Length);
                    Byte[] arr = Convert.FromBase64String(att.rawData);
                    bytesRead = Math.Min(buffer.Length, (arr.Length - (int)offset));
                    Array.Copy(arr, offset, buffer, 0, bytesRead); //The error happens here, because of the Math.min just a line up.
                    if ((int)offset + bytesRead >= arr.Length) //don't mind this if, it's for my caching system.
                        alreadyIncrementated = false;
                    return DokanResult.Success;
                }
                bytesRead = 0;
                return DokanResult.Unsuccessful;
            }
            bytesRead = 0;
            return DokanResult.Unsuccessful;
        }