That doesn't quite make sense. Most DVDs are encrypted, region lock is implemented in DVD encryption, that is usually the problem encountered by most ppl, especially regarding imported discs. But you claim it's not region lock issue...
It could be that Win 10 doesn't come with the decryption code/key just so Microsoft can save a couple dollars on license fee. I might have encountered this problem some years back with a brand new company laptop. What I taken for granted (DVD playback) was unavailable on the system out of box. I searched around and found that many commercial software bundle the code/key for decryption, but had to dug around more to find a free (could have been cracked software I can't remember) version.
Sorry seems you aren't getting the help you need. Because hardly anyone have that problem. When I buy a disc, I rip it once and make an MP4 out of it, and then put the DVD in original case away for long term storage.
I believe VLC player is a fine "container" app, but for playback (like all media players) it relies on codecs which might or might not have been bundled.
Well I'm telling the truth- whether or not you choose to believe me is up to you. I'm just stating the issue I'm having.
My DVD drive is set to Region 2.
The main issue is the encryption of newer JAV DVDs. I have no problem with most pre-2010 titles. This issue happens with both ISOs I've downloaded and with physical discs.
Just tested with IPTD-999 (released 2012), which works no problem.
IPZ-275 (released 2014) does not load.
IPZ-390 (released 2014) does not load.
I've tested these DVDs in my Japanese PS2 when I got them originally and they worked fine. Now though even with my region set properly I can't read them on my PC (haven't tried again on PS2, but I keep the discs stored safely and they are flawless).
Back to the drawing board for me I guess. I really appreciate everyone's suggestions!