Hey, there sorry for the necro, I've been having similar problems that the OP's had but I've been trying with my local set to Japanese. Any idea what to do in that situation?
Assuming you've already made sure you've applied the correct crack to the correct file as I mentioned in points 1 and 2, and set your computer to the Japanese time zone like I said in point 3, there are a few more ideas you can try.
4. It may be that your computer does not meet the requirements for the VN, or that there was some kind of file corruption or other error between the original software and your copy. Most modern visual novels have free trial versions available for free on their website. Look for the text 体験版, the Japanese word for trial version, and obtain a copy. In the event that distribution of the trial version has ended, you can still usually get a copy by means of archival sites like Holyseal or even downloading a copy saved to the servers of a service like the Wayback Machine. Googling 体験版 in addition to the game's Japanese text may also be helpful, as well as checking out the links to the trial release on VNDB.
Once you have your trial installed, boot it up. If it doesn't work that means we can conclusively say that the problem is not with the crack, although determining what IS causing the problem is going to be very difficult and you might just want to try it on another PC and see if it starts working for no reason. If the trial version works fine, that means that the problem is definitely with either the crack or your copy of the game. Before troubleshooting further, at this point I'd recommend just playing through the trial mode so you can determine for yourself wheter the VN is really good enough to be worth all this effort. (Or even maybe so good you want to buy it!)
5. At this point the problem is either with the crack or your copy of the VN. If you have multiple different cracks, you'll want to try each of them sequentially on every copy of the game you can find.
6. If nothing works at this point it's pretty likely that the crack has been made for a specific version of the game in mind. Many cracks will only work with an unpatched version of a VN, and some will only work with a VN that has a specific patch. Look for documentation and experiment.
7. In extreme circumstances, some Japanese games have been known to check what language you used in the Windows OS install prompt. Reinstalling your OS is probably too far to go for a long shot chance at stealing a visual novel, but it may be worth keeping this in mind the next time you set up a PC for VN usage.
8. Begging. While you may find begging pathetic or beneath you, if you are honest, specific, nice and briefly explain the lengths to which you have already gone and how insane not being able to read this VN is making you, the success rate is astonishing. 4chan has an entire board dedicated to requests; other forums usually have similar areas. I got myself a copy of ユメミルクスリ from a begging thread on 4chan back when you couldn't find that VN anywhere. Begging works. In fact, someone may have already begged a prepatched copy of the VN you want off of someone else, check the archives!
9. Acceptance. Visual novels are a niche medium and so is cracking. Many VNs go years without ever being cracked. Where a crack that has issues for a Triple-A video game will be fixed within hours, VNs sometimes have to wait decades for the same treatment. Even if it is impossible to purchase this particular VN for financial or legal reasons, there are literally tens of thousands of visual novels available for free on the internet, some of which you will love more than this particular book. As you read more a VN that you once longed to read with obsessive passion can become merely quaint in the face of the books you've read in the meantime. Even if your desire never fades and the crack is never fixed, you will always have the opportunity to purchase it a few years down the road when your financial or legal situation has improved. The price is likely to have dropped substantially by then too!
