Forgive me if I'm wrong.... But 2.5.x or lower that 3.0.0 is obsolete chain will die stop and cause faults if you stake 1 block. Moving from a 3.0 back to 2.5 also will break your database files. Windows was compiled with Berkley and level dB the same as Linux does libleveldb. A libmemenv. A and all that jazz. Sounds like you have destroyed your block data and all you can do is update from the snapshot provided head to
http://discord.Me/netcoinAs you can see above and other posts throughout MANDATORY UPDATE MEANS MANDATORY
running a sub version will cause problems at the above mentioned block height.
More updates to come soon.
Please come to the discord for info and to keep upto date.
Close to archiving this thread as well I and other team members rarely come here any more.
Thanks.
Also as side to this I run v3 on mac Linux Windows all without a hitch however all systems have over 20gb ram and plenty of cpu overhead. Only issue I do have is gui crashes due to gnome it freezes but comes back on all coins I run. Pi and single boards don't run the gui well.
Oh and the code uses ssl v1. 0.2 and compiled with the latest boosts and Berkley databases no longer uses 4.8 (personally anyways) and release binarys