Issue with Epson V850 Scan Software 3.9.3.2 (Win10/64 bit)?

It runs fine on my XPS8500. Do you use any maintenance utilities?

 

I run Advanced System Care https://www.iobit.com/en/advancedsystemcarefree.php and occasionally CCleaner https://www.ccleaner.com/ Microsoft calls them "snake oil" but they help.

Windows has some builtin utilities that fix problems that cause programs such as Epson scan not to run properly. They are System File checker and Deployment Image and Maintenance Tool. They are run from the command line of Administrator Command Prompt.
The syntax is:
sfc /scannow
and
DISM.exe /Online /Cleanup-image /Restorehealth
run sfc up to 3 times in succession to fix problems then dism.
These can be verified on microsofts support site.
The problem you are experiencing is in Windows not epsonscan.

The easiest way to get an administrator command prompt is to right click the start button.
Will not harm your computer, will likely fix it.

The latest Windows system upgrade installed correctly on 2 of my 3 computers but the 3rd I had to manually delete the update files and redownload them.

 

I run those utilities in safe mode with networking also to ensure everything is good.
Drive booster https://www.iobit.com/en/driver-booster.php solved some slow startup problems for me.
The creators update was a year ago and some drivers supplied by Windows driver store are old. The problem may be in the USB controller which will show good in device manager or similar component in the computer that uses a separate driver.

Once Windows has been verified to not be corrupt and all drivers are up to date its time to contact Epson support with an accurate description of the failure(s).

 

A few years ago similar happened with my V700 and Win10 64 bit. About a month or two later after a bug fix in Microsoft's monthly update the problem went away.

If doing some serious scanning I turn the internet OFF, by disabling the lan connection in Windows or unplugging the cable from the router. Background services can start running and disrupt the scanning as it sees the computer as being idle.

 

My V700 started to warm up too often during scanning then epson scan started to freeze - restart and it's scanner not connected so i moved it over to my Imacon win 7 PC that is for scanning only, and absolutely no problems there . . so i have a V850 pro that is almost useless at the moment - done all the things i can find in google - might try removing the cable next time

 

I've had two problems in the past after a Windows Update that were corrected in Settings, lock screen changed background picture - settings showed my choice but a different one was selected and grayed out when the list of options was opened, the programer's setting was in use not mine. Audacity would not recognize any microphone, a privacy setting had changed that I did not change. Windows feature updates always disables my Windows 7 installation and I have to reinstall it. No help in Windows Support or HowToGeek.com for your scanner problem. SO with the scanner connected and turned on
1. right click the start button and select Device Manager
2. right click the scanner in the list (expand as necessary) and select Update Drivers
3. Select Brows My Computer for driver software
4. Select Let me pick from a list of available drivers on my computer
5. Highlight the latest driver (or the one you want to use / try) then click Next, that driver will be installed for that device.

This may not solve the problem but it won't hurt.
I have a V700 on Win 10 and Plustek 7600i on Win 7 on this computer and a V500 on a different Win 10 computer.

 

I got an updated version through their website of the silverfast software that came with the V850 and googled some more and noted that it relied on the driver/s supplied by Epson for the operating system - so i turned to Vuescan and it is a nasty $89 US for the full version and i had a good look at the various vids and noted you cannot batch scan like you can on epson scan - i really like the simple straight forward controls = levels and sometime curve tool use - looks like i'll wait until they get off their backsides to fix it - i have contacted epson it's not even a month old looks like more phone calls