Recovery works just fine.
There are few possible scenarios why this happened:
a) coins were moved from your wallet- check transactions history
b) you mined those coins on some side-chain that was not the main chain and therefor disapeared when you synced to main chain
c) you have 2 wallets and forgot about it
I dug in several wallets. I controlled the complexity of the found blocks so that the chain was the main one. A friend from another city has exactly the same story: 90-95% of coins are lost. In version 0.1.7.5 they are, in the later there is not. For this reason, I stopped getting a coin: I lost about 5000 BLUR.
The representative of the wallet developer refuses to recognize the problem. Presumably, the problem exists only in the windows version of the wallet.
Another chain is impossible: on each machine had its purse and couldn't they all prove the alternative chain.
You did not update your binaries, which put you out on a chain that was not the main chain. It sounds like your friend did the same with untimely updating. There have been 3 releases since v0.1.7.5 -- 4 if you count the most recent update. With regard to this statement:
. I controlled the complexity of the found blocks so that the chain was the main one.
This logic does not hold up to reason. You can find blocks on any blockchain, and if a superior proof of work is found to your own, the valid blocks you found, or "uncle blocks" will be reorganized out of the chain. I do feel that is a bit unfair, which is why we are considering implementing some of the changes Masari did with uncle mining. However, that's not going to be any time "soon" in all likelihood since our reorganizations are never longer than 2 blocks, historically speaking.
The representative of the wallet developer refuses to recognize the problem. Presumably, the problem exists only in the windows version of the wallet.
I believe I have addressed nearly all of your concerns. The problem could be solved using a solution I've offered a few times now. Join our channels for timely announcements (we have reddit, telegram, twitter, and discord) all of which receive every announcement we make -- reddit and twitter often are the last to receive those announcements, so I would recommend Telegram or Discord for real-time information. I am active on both every day.
This issue doesn't affect only Windows. We've only had one issue which affected only Windows. The wallet incompatibility from v0.1.7.5.1 and up was a result of a more secure password container (which means your coins get stolen less easily). Security of your coins is our paramount concern, there... Actions taken by our network are always going to reflect that. 99% of our users have not experienced any issue with keeping valid coins. The coins you mined are not valid on our network because changes have been made. This happens with every hardfork. If you upgrade prior to the fork height, you will remain mining on the main chain.