Tinkers construct/Mantle is causing an issue with Sophisticated Backpacks upgrades, only those that operate every tick like the feeding and compression upgrade, and more specifically when putting the backpack in a Curios slot oddly enough. This does not happen when Mantle/Tinkers is not present.

Post a link to the actual crash report, don't post a screenshot of it.

In any case, there is no way Tinkers' is causing that crash. Their mod is probably just coded so weirdly that it relies on mod load order to decide whether to crash or not; or they are assuming that other mods items are theirs without checking. There is no code path in my mod that would allow fixing that.

That, or you need to update one of their mods. No such method error usually means updates are needed.