Board Thread:Questions and Answers/@comment-15695624-20140531005941

For those who have to play offline because they are using the old launcher with a batch file, for example, the fix for disappearing inventories in the Alchemy Bags works perfectly.

I was playing using the mods from Season 4 of Direwolf20's Let's Play, which is using Minecraft 1.2.5, and is in neither Tekkit nor FTB. I was originally using MultiMC with this setup, but I was never able to get another of my favorite mods, Single Player Commands to stay installed using it, so I created the batch file, which also addresses the memory issues in Minecraft.

After having renamed my old .dat files with my online name to Player, then deleting the new ones created, I was once again able to get access to all my items. 