>>>>>>>>>As for the SMB issues, I've deactivated SMB v2/3 on the (virtual) server, but doing so also prevent the users from accessing the server.
>>>>>>>>
>>>>>>>>That hints for me to deactivated SMB1 - perhaps double check ?
>>>>>>>>You NEED SMB to access remote files, but only SMB1 is ISAM safe...
>>>>>>>
>>>>>>>If I understand you correctly, I should deactivate SMB2/3 and let only SMB1 activated?
>>>>>>>
>>>>>>Correct
>>>>>
>>>>>If I deactivate SMB2/3, the users can't acces at all the server
>>>>
>>>>Then you have a screwed up system: NT, W2K and XP did just that with SMB1 ;-)
>>>
>>>What do you mean by screwed up system? The server is Windows Server 2016 running in a virtual machine (VM) and all our user are using Windows 10.
>>>
>>>We're beginning to think that having the database on the VM is the cause of our problems. Maybe transfering the database on a "real" physical server will resolve the problem?
>>
>>same system as in "Index jeep corrupting" thread?
>
>Yes

Gimme 60 min to think options through while getting some fresh air and buy groceries - have some ideas, but must put them in effort/possible solution percentage order, which is not easy having no further info about # of users, HW system and net wiring stats, SW/app complexity.

Are your data accesses hardcoded xBase / vfp commands and functions scattered directly in your code using text literals ?
How are paths/filenames built in your system ? Logical Disk letter "net use", SMB share names or IP URIs ? Easy to fix via variables fed to functions/methods ?
Anything more about net wiring/setup, Server VM and typical client machine # and HW helpful