Not sure if this helps. I have both a ProPlus 2 and ProPlus 3 computer and download dives to Oceanlog 2.x running on a desktop PC.
I needed Oceanlog installed on a laptop in preparation for an extended dive trip which would have exceeded the memory capacity of these ProPlus units; therefore, needing a way to download dives while travelling.
I used the Oceanlog 2.x installation file which I had on the desktop. Transferred it to the laptop and ran it. I looks to me to be still the same file that is available direct from the Oceanic website. This software does not appear to have been have upgraded beyond version 2.4.9
The installation went smoothly and I could open all my previous logged dives as well as backups. However, as soon as I tried to connect up the USB cables to test a data transfer, I realised that the USB drivers for these USB connectors had not been loaded (the same driver is used for the different cables used by ProPlus 2 and 3).
I clicked on 'Install USB driver' from the top menu and that installation failed with an error message from Windows Security saying that the USB driver was blocked from installation because it violated a "memory integrity" setting in Windows Security. This is obviously a more recent Windows Security setting than was present on my Desktop, but now installed and active on my newer laptop.
Luckily, it is possible to turn off the "memory integrity" setting in Windows Security. I did that and then the USB driver provided with Oceanlog 2.x version 2.4.9 installed smoothly. The cables and test downloads from both ProPlus units, using their respective connecting cables, worked.
Once installed, this USB driver for the connecting cables prevents Windows Security from switching back on the "memory integrity" setting again. It says you need to install a compatible updated driver by trying Windows Updates or by receiving an updated driver from the manufacturer. I have been unsuccessful here.
This situation will be fine for me for this travelling trip, as I can get around not having this setting turned on temporarily. I will update on the situation here if I learn more.
In summary, it is possible that the problems reported on this thread are being caused by the USB connector driver conflicting with a new Windows Security setting. Everything else appears to work fine. Hope that helps.