Does updating a modpack's component mods cause trouble?

[Ieldra]

I recall the time when this just wasn't done. When the only way to update a mod was to remove it from your pack, load your world losing all the stuff you made with that mod, and re-add the new version.

Meanwhile, last year I frequently updated an existing pack and world with new versions of Reika's mods, resulting in no trouble at all (except for some of the mod changes ), while earlier this year, I couldn't update Buildcraft Additions without going through the old process.

So what's the rule? I'm running a modpack with quite a few "release candidate" versions which have updated to their release versions since then. I would like to update but the modpack authors haven't seen fit to include the newer versions.

Also, I'm hearing something about a change in MC Forge related to fluids that (apparently?) makes mods using earlier versions incompatible with those using later versions. Do I now have to wait until all mods I have in my pack updated to the newer version before I can update even one of them?

 

[lenscas]

I have never needed to first remove a mod before updating it, but most of the time if something like that is needed it is at least said in the change-log from said mod.

I have no idea about the forge thing but if liquids are handled differently then I would not be surprised that every mod that uses liquids needs to be updated to that forge version.
You may/probably can get away with not updating mods that don't interact with liquids in that case but I have no idea about this subject.

 

[Zarkov]

I would say that there is no rule, this is different depending on mods, and even on which versions you are changing between.

Basically, just do a backup (world + existing mods and config folders) and upgrade everything. Then (if the server starts) take a quick look at the things you've built using the updated mods.

I have to say I'm fairly impressed with how stable mods tend to be in general. I updated Buildcraft quite a bit when I had quarries running and everything, without issues.

 

[darkeshrine]

Also, I'm hearing something about a change in MC Forge related to fluids that (apparently?) makes mods using earlier versions incompatible with those using later versions. Do I now have to wait until all mods I have in my pack updated to the newer version before I can update even one of them?

That happened a while ago. Looking at the Forge site, as of 1.6.2 liquids changed to fluids. Are you using a pack older than 1.6.2? Typically, updating from one minecraft version to another(like 1.5.2 to 1.6.4) would require a pack rebuild rather than an update.

 

[Fuzzbling]

Forge "Build 1.7.10-10.13.3.1372-1.7.10" and later is where all the new fluid changes start (I think). If you are going to update any mods in a pack, you will need to review the changes for them and see if their recent versions are built using one of these later versions of Forge. Some mods (Forestry for example) are not updated to use the newer Forge 10.13.3.x builds, so updating mods with co-dependencies on other mods that are not updated yet, will result in crashes, etc.