I originally reported this as a comment to MC-56310 on August 5, 2014. MC-56310 was resolved as "downgrades not supported". I understand this from the perspective of a bug against 14w31a but after further reflection I decided that a much more appropriate place to enter this issue report is against the launcher itself. For it is the launcher, not the Minecraft snapshot, that allowed for the deletion of all my inventory, out of all chests, etc.
I had this happen to me today with a world originally created with 14w31a (the lastest as of today). I accidentally re-entered this world after changing my profile to 1.74 Vanilla. The result was that my built world was intact but all inventory items from my person and all chests throughout my world were empty.
I reset my profile to 14w31a and re-entered my world again. All my inventory was still empty. Luckily I had saved a backup from earlier that day so I was able to recover somewhat.
The Minecraft launcher allows for multiple profiles for a given user, each with the option to set the Minecraft version. What I did was an accident but an accident that I believe will happen a lot in the future.
I entered a 14w31a world under a 1.74 vanilla profile and the Minecraft Launcher gave absolutely no warning that my versions didn't match. This alone should be considered a bug, in my opinion. Had I been issued a warning I would have immediately remembered that I needed to change my profile back to 14w31a.
Since different Minecraft versions are supported by the Launcher it seems to me that proper care should be made by the Launcher when catastrophic changes can be made by entering a world under the wrong version.
Of course the user should still be given a choice to proceed or not so all I am really asking for is a warning message and a prompt to continue or not.
Bob
Linked issues
Comments 8
I opened
which is semi-related but more inclusive that this snapshot bug, because it targets the root of the problem - world save filess not even storing the version number in the 1st place, and thus affects all versions, snapshots AND release.
But basically Mojang answered with a "That ain't a bug - user should just be careful and deal with it." i.e. the typical "blame the end user for merely using the program's built-in features" (i.e. combo of launcher multi-profile capability + simply opening a world within the game).
Well, the fact that I presented it as a bit of a long rant sure did not help me case lol. I hope you have better luck here.
PTR_91: Let's assume that typical user isn't as knowledgeable and disciplined as, say, yourself. Let's say, a typical 10 years old kid playing on dad's computer. Or that typical user doesn't have perfect memory. Say, forgetting to simply switch back the launcher profile hitting Play and starting playing. Then imagine imagine that while YOU didn't have any problem, that your superior brain makes you not representative of the 10+ millions MC players, and try to open your mind to the possibiity that hundreds of thousandsa of players actually got their worlds corrupted. Then insist that a workaround is an actual solution, and blame the end user again.
I appreciate both Ray's and Patrick's comments. I do hope that steps are taken to somehow lessen the impact of an "operator error".
To PTR_91 I have to say that from my perspective as a retired software engineer from an Operating Systems lab that this defect is similar to formatting a USB drive on Windows 8.1, storing some important files on it, and then transferring the USB drive to a Windows 8 system and find that the contents of these files have been cleared but the files themselves remain. Just because something might be considered operator error doesn't mean that steps should not be taken to prevent it--or at least properly warn the user.
The solution Mojang implemented to solve PROGRAM Version Control problems was to put different versions in their own folder.
Example: minecraft/versions/every_profile_you_ever_created/
The same solution would work for MAP Version control as well.
Example:
minecraft/saves/1.7.2
minecraft/saves/1.7.4
minecraft/saves/1.7.10
minecraft/saves/1.8-14w24a
minecraft/saves/1.8-pre1
When you open your 1.7 world with 1.8...
1) You get a warning
2) The map gets moved to the 1.8 version folder you opened it with.
3) Moving the maps is 1 way, can only move to a higher number folder.
When you run 1.7.10, or older, none of the 1.8 files even show up. in the list.
Only 1.7 and older. If you run an older version like 1.6 newer worlds simply don't display in the list.
Ray,
I suppose your offered solution would work but I'd be happy with just 1) You get a warning.
Also I'd change your step 2 to copy, not move.
What's fixed:
I just ran snapshot 15w34c and they added "Version: 15w34c" to the world selection screen screen, indicating the last MC version the world was loaded with. Older maps say "Version: unknown." Also If you hover over a world ICON you get the popup message "Don't forget to backup this world before you load this snapshot."
What's still broken:
Unfortunately, They did not activate the popup, over the text area so if you select a world text, and press the Play button, you never see the warning.
Proposed Solution: Add the same popup message to the "Play Selected World" button when appropriate.
This is not a bug in the launcher, it is a design flaw in the map selection menu. The new launcher has made it very very easy to corrupt your old worlds.
Every map created with should contain a record of the Minecraft version that generated it and The last version that opened it.
That information should be displayed on the map selection screen.
When the user switches profiles and tries to select a map created with a different version of Minecraft The program should perform the following test.
Pseudo code.
If (client_version <> map_version) {
Prompt_User {
"The selected world (Version 1.xx.xx) is incompatible with this version of Minecraft.
Your world may be corrupted." [Continue?] [Cancle]
}
}