A strange situation that has suddenly occurred. From what I can tell we have not changed anything to cause the issue. Server is a Windows Server 2016 standard. The clients are Windows 10 x64. When pcs first boot in the morning, one of the three mapped drives has a red X in the drive mapping when viewed in file explorer. If you double click the drive letter you can still access the contents. However, the red X never goes away. The only way to rectify the situation is to manually disconnect the drive. Which from what I have seen doesn't actually remove it from the file explorer view. However, if you then reboot, then the drive mapping appears normal. In addition, there was once instance where suddenly in the middle of the day, the red X reappeared for one user. This has been going on for about a week and a half. The worst part of it is that the Quickbooks 2017 application does not seem to like the red X situation. If the drive mapping has the red X, then Quickbooks will not let users open any of the datafiles on the server. However, once the drive is disconnected and the pc reboots, Quickbooks works fine. I am looking for any advice as to what could be causing this issue and how to correct it.