Apologies, I should have given more precise information about the software, including the database and PC I am running it on, which is the same since I transferred the software to in June 2018 after the last PC died. At this time I had to update the MS SQL server software to the 2016 version and this is what I last discussed with Adrian Fletcher at that time.
So, PC on which the software (version2.2G) has been running successfully up until a week ago is:
Dell OptiPlex (Intel(R) Core(TM) i5-4590S CPU @ 3.00GHz, 3.00 GHz 64-bit operating system, x64-based processor, running Windows 10 Pro, version 22H2, installed 22/11/2020. Database is Microsoft SQL Server 2016 (Media X64). Nothing else has changed other than Windows has been running its regular updates automatically.
I have tried running the compatibility settings mode and that made no difference. Unfortunately, I don't have an old pc / laptop to try running it on. I haven't tried to extract the data from the database, would rather leave that as a last resort.
Any other ideas?
See if you can find any log files that it spits out, otherwise you're in the dark. my best guess is that seeing as the software is written using the .NET framework there's probably something that has been deprecated and/or removed which was included in a windows update if nothing else has changed on the machine. It might be as simple as just installing an older version of the .NET framework, but hard to tell with no output!
If you can find any logs (or anything printed out if you run the .exe file from a cmd line) stick them here and I'll try and dissect them.