Check Windows Defender Exclusions, Windows Updates & problem PC network cable / switch.

This error occurs when BDE Paradox reads an invalid number of bytes of data. It is a very low level / odd issue, and not one that we can resolve via our own software changes.

We have seen this occur a handful of times since mid September 2019. All on Windows 10 1803/1809 workstation machines, but not other computers in the same practice.

We believe a September 2019 Windows 1803/1809 update / Windows Defender update has caused the issue.

Ensuring that the Medilink share on the server is excluded from real-time scanning, especially in Windows Defender is the first priority. Step-by-step instructions available here:

Updating to Windows 1903 also seems to resolve the issue and is the second priority. Alternatively you may choose to roll-back recent updates.

On the first site the issue was resolved temporarily by simply relocating the problem machine next to the server with a new (good) cable and switch - indicating that cabling/hardware can also play a factor.

Re-installing the BDE from scratch may also help, i.e. renaming the existing Program Files\Borland and Program Files (x86)\Borland folders, then installing BDE (BDEInfoSetup.EXE), then using C:\medilink32bnt\bin\ChangeServerBaseDir.EXE to re-point to the Server Base Directory (i.e. \\SERVER\MEDILINK).