modpack not working: missing id for simplyjetpacks

[caspotron]

for some reason i cant log in to my custom modpack.
i updated it to add a couple mods including chissel 2, i started the server and loaded the server but my client couldnt load chissels. i fixed that by updating my videocard driver but after readding it my minecraft cant connect the the server as it says fatally missing blocks and items.
the consol shows this:
[20:34:03] [Netty Client IO #2/INFO] [FML]: Attempting connection with missing mods [AromaBackup, journeymap, notenoughkeys, ResourceLoader] at SERVER
[20:34:05] [Client thread/INFO]: Connecting to 84.107.191.7, 25565
[20:34:07] [Netty Client IO #3/INFO] [FML]: Server protocol version 2
[20:34:08] [Netty Client IO #3/INFO] [FML]: Attempting connection with missing mods [AromaBackup, journeymap, notenoughkeys, ResourceLoader] at SERVER
[20:34:08] [Netty Client IO #3/INFO] [FML]: Injecting existing block and item data into this client instance
[20:34:08] [Netty Client IO #3/INFO] [FML]: Found a missing id from the world simplyjetpacks:jetpacksEIO
[20:34:08] [Netty Client IO #3/INFO] [FML]: Found a missing id from the world simplyjetpacks:fluxpacksEIO
[20:34:08] [Netty Client IO #3/INFO] [simplyjetpacks]: Loading configuration files
[20:34:08] [Netty Client IO #3/ERROR] [FML]: Failed to connect to server: there are 2 missing blocks and items
i have tried everything but i just cant get it to work.
any help would be highly apriciated.

 

[lenscas]

first, make sure simply jetpacks works in singleplayer.
if it does, temporarily make a new server with a new world and see if it works on that.
if it does try the old world on this server(make a backup first)

 

[caspotron]

first, make sure simply jetpacks works in singleplayer.
if it does, temporarily make a new server with a new world and see if it works on that.
if it does try the old world on this server(make a backup first)

ok, single player does work but even after remaking the server with fresh files, it still gives the same crash message.
removing simplyjetpacks also works but i would really like to keep it. any other ideas?