plowmanplow

Always provide the API URL or a link to your custom modpack page when requesting assistance. The /bin/ folder should only contain the file modpack.jar. All mods go in or below the /mods/ folder. Your ChickenBones mods (CodeChickenCore, NEI) are named oddly (not what the author names them). The implication is that you didn't get them from the correct location. Get the latest versions for Forge/MC 1.7.10 here: http://chickenbones.net/Pages/links.html

Always provide the API URL or a link to your custom modpack page when requesting assistance. The /bin/ folder should only contain the file modpack.jar. All mods go in or below the /mods/ folder. Your ChickenBones mods (CodeChickenCore, NEI) are named oddly (not what the author names them). The implication is that you didn't get them from the correct location. Get the latest versions for Forge/MC 1.7.10 here: http://chickenbones.net/Pages/links.html

Client Pack:
Your modpack is more than twice the size it should be because you are including too much in the archive file. The modpack archive should only contain the folders: /bin/, /config/, /mods/. The /bin/ folder should only contain the file: modpack.jar Client Only Mods: (remove these mods on the server)
Better Foliage Custom Main Menu Holo Inventory Thaumcraft NEI Plugin After removing those mods from the server's /mods/ folder I was able to start up a Forge 1.7.10_1272 server and connect with your client with no crashes.

What now? As previously mentioned, you go through every mod in your pack and make sure that:
each mod is the latest compatible version each mod is downloaded directly from the mod author's preferred distribution channels For mods that aren't cornerstone, "big name" mods make sure that you take a look at what folks are saying or complaining about. If a mod has a ton of folks complaining about instability or incompatibility with other mods you might want to steer clear. At this point I would normally bring the pack up in my test environment, but there are so many outdated mods with known critical issues in your pack that it's not reasonable to do that at this time.

What now? As previously mentioned, you go through every mod in your pack and make sure that:
each mod is the latest compatible version each mod is downloaded directly from the mod author's preferred distribution channels For mods that aren't cornerstone, "big name" mods make sure that you take a look at what folks are saying or complaining about. If a mod has a ton of folks complaining about instability or incompatibility with other mods you might want to steer clear. At this point I would normally bring the pack up in my test environment, but there are so many outdated mods with known critical issues in your pack that it's not reasonable to do that at this time.

@CharZinta:
 
If you create a modpack archive with Forge for 1.7.10 and select MC 1.7.2 in your pack settings the Launcher will get the libraries and minecraft.jar for Forge/MC 1.7.2 and then try patching that with Forge 1.7.10. This results in unexpected classes and structures and throws that exact error. Now, this may not be what OP did, but it is highly likely. We won't know until he either admits that he corrected the version number and the pack works fine, or he posts his API URL and we can examine it ourselves.

You are going to have a challenging time finding combinations of each mod which will work in the older versions of Forge. Trying to set up a current 1.7.10 pack on Forge #1217 is going to be an exercise in frustration.

Update TiCToolTips to version 1.2.3. (just came out today) Reika (wrongfully, IMHO) includes the Waila API files in his DragonAPI JAR. These are outdated and causing the crash. You can fix this by opening the DragonAPI JAR file and removing the "mcp" folder and its contents.

Many of your mods are woefully out of date. Update all of the mods for which new versions are available. OptiFine often causes issues. Try removing that if the updated version doesn't help. Crash reports are required in order to anything other than guess at the root cause of the issue.

All public Cauldron distributions are under DMCA. Specific information about where to get them may not be shared here.

You need to add the legacyjavafixer-1.0.jar to your pack to make it compatible with Java 8.

The contents of your modpack are in a subfolder named "Death Surrounds". The required folders (/bin/, /config/, /mods/) must be at the top level of the folder structure inside the modpack archive. You have two different versions (3.0.6.232 and 3.0.7.256) of all three Galacticraft mods. Remove the older versions. I highly recommend updating to the latest AE2rv2 and ExtraCells mods. You have multiple mods named BlahBlah-1.7.10.jar. Almost no authors name their mods this way. However, many mod scraping websites rename their mods in that fashion. The implication is that you aren't getting the mods from the author's preferred distribution channels. This is always bad and often results in old versions of mods (your case) and increases your risk of getting malware on your PC. You have the MDK ZIP file. This is the Mekanism Development Kit and is only for use by mod authors. It should not be in your modpack. Your "Modular-Powersuits-Addons-Mod-1.7.10.jar" file is actually MMMPS Addons for 1.6.4 with a renamed file name. Okay. I stopped at this point and did not attempt to run the pack. It's obvious that this pack has never been successfully started. Nearly all of your mods are either quite out of date or are from sketchy downloads. You need to build the pack methodically. You cannot just grab 130+ mod files, throw them in a /mods/ folder and expect the pack to work. This post should help you:

Yes, indeed. I would recommend starting with my BareBonesPack for 1.7.10:
 
That link walks you through the process of making a complete modpack with by BareBonesPack.

You need to add Lexmano's Legacy Java Fixer to your /mods/ folder.

For whatever reason, VoxelMap is having trouble accessing or using your network interfaces. Not sure why it would even be trying to do that. Since it is only a client/visual mod, you might try disabling VoxelMap just to make sure that it starts without that. If it does, try a different minimap.

I didn't want you to think that no one is looking at this. I verified the process by which the platform attempts to validate a direct URL to a monolithic modpack archive. I implemented that process in a test environment and your " http://magfilms.co.uk/magpack/6.3.zip " link should be valid. I've been in communication with the web devs and they are looking into things on their end.

Just to make sure someone doesn't see this and think that copy.com doesn't work:
 
copy.com works just fine as long as you create your URLs properly. Share the file and get a copy.com public URL. Append "?download=1" (without quotes) to the URL and you have a direct link that will work with the platform.

The Mystcraft API is only for use by mod developers and should not be in your modpack. Your Mekanism build is very old and has known major issues. This should be updated to 6.0.5.46. Your CoFHCore has an odd file name and does not match the version of Thermal Expansion in the pack. The implication is that you did not get the mod from the author's preferred distribution channel. This is always bad. Get the latest 1.6.4 version (2.0.0.5). You are missing Universal Electricity mod which is required for the 1.6.4 version of MFFS, and your Calclavia Mods are out of date. You should updated them all to the latest 1.6.4 versions... The state of affairs with Calclavia's mods and ICBM (no longer maintained by Calclavia) is a hot mess. Some of Calclavia's domains no longer work and many of the links from his pages are nonfunctional. I do this all the time and it still took me 45 minutes to find working, matching versions of all of the Calclavia related mod which worked correctly together. In order to save you a lot of time, I have assembled a ZIP with all of the Calclavia related mods and a new full set of deconflicted config files. Remove your version of MFFS and Resonant Engine and use the files from my download. I also tossed in some NEI helper mods along with Waila. Feel free to remove them but they are super handy.
 
Calclavia Mods for 1.6.4: https://copy.com/cjqfNUKCNyoR72AE?download=1
 
Give all that a shot and come back if you are still having troubles.

This post goes over the process I use for building and testing packs:

Shall we guess or use a ouija board? Please provide the link to your modpack page so that we may properly assist you.

What The_Doctors_Life said.
[19:32:33] [Client thread/ERROR]: Caught exception from ReactorCraft Reika.DragonAPI.Exception.IDConflictException: The mods were not installed correctly: CONFLICT: Potion IDs: biomesoplenty.common.potions.PotionParalysis@3de02302 @ 31 Check your IDs and change them if possible. You have a potion ID conflict. This post on resolving ID conflicts should help you. The method for resolving block/item ID conflicts is the same as with potions:

For monolithic archive hosting (one big ZIP file) copy.com works very well.

You should probably be using AE2rv2 instead of AE2rv1. Nearly all your mods are named simply <modname>-1.7.10. Almost no mod authors provide their mods with names without version numbers. The implication is that you aren't getting the mods from their respective mod authors. This is always bad. Your versions of OpenBlocks and OpenModsLib do not match (see previous bullet point). Update the latest matching versions. Gravity Science mod requires Grim3212 Core mod. Get both from the author's website. You have an ancient version of MFFS and are missing the required dependency library Resonant Engine. You have (and amazingly ancient version of) Tinker's Construct mod but not the dependency mod Mantle. MCHeli is not installed properly.

Your modpack archive should not include the /bin/minecraft.jar file. This is not needed and is a violation of Mojang's EULA. You should not include the /mods/VoxelMods/ folder in your modpack archive. This will overwrite client's local settings when the pack updates. It is seldom a good idea to change the names of the mod files distributed by authors. Your CodeChickenCore mod has an extra "(3)" in the file name. That error log shows errors when attempting to extract/open all your TeamCoFH mods. Please re-download all their mods. Make sure you are incrementing the pack version number any time you change your modpack archive.

Your PermSize options are messed up: -XX:PermSize=3096m -XX:MaxPermSize=4000m You should not be allocating 3-4G of RAM to permanent generation space. Your Better Dungeons mod is not installed correctly. Open the ZIP file and follow the instructions. The Warp Mod is not installed correctly. The ZIP file just contains a JAR file. I think the Moden Weapons Pack has a conflict of some sort with either another mod, or SMP in general. It is throwning an error related to data persistence when placing vehicles from that pack. I removed that pack and added FC Pack addon and was able to place vehicles from that. Might need to take the issue up with the Flan's group.