DavidM

Stop bumping your thread every hour or so. This will be annoying to others, thus reducing the chance of getting help. Thaumcraft is causing the problem. Update to the latest version of the mod. If the same error still occurs, remove Thaumcraft and report to its author (don't think Azanor is still doing modding but meh). 1.7.10 is no longer supported on this forum. Update to a modern version of Minecraft to receive support.

Please stop bumping your thread every hour or so. This will be annoying to others, thus reducing the chance of getting help.

Please post a screenshot. It sounds like you've accidentally downloaded some virus instead of Forge. Make sure you only download from https://files.minecraftforge.net and make sure you don't click on ads instead of the actual download.

Please read the EAQ and post the crash log.

https://stackoverflow.com/questions/5774970/run-jar-file-in-command-prompt

Wut? Why are you opening a jar with a browser? Try running the jar in the command prompt.

We need more information. What does the console say when you ran the setupDecompWorkspace command? What version of Minecraft are you modding for?

Post your code.

Those errors are syntax errors, and are caused by not writing Java correctly. They did not occur because the tutorial is outdated. To fix such errors, please learn Java.

The size of the sword can be edited in the item model json.

That is not going to compile. 1. An event is not a block. 2. Use the blocks in the Blocks class instead of Block::getBlockFromName.

I see. I'm doubting whether syncing the entity movement will make a difference, since the hard-coded limit will remove the entity if it goes too fast (and considers it as "moving wrongly"), which will still be the case if the entity is synced. I'm not sure whether this can be achieved without a coremod, but my thoughts are along the lines of creating a EventSubscriber that stops the broom from being killed. Not sure if this would work tho. Calm down tho...

By checking if the world is remote, you are only executing the if statement on the client side. You probably meant to inverse this.

Please stop bumping your thread like this, as it can be annoying and unnecessary. Packets. However, I am not exactly sure what you are trying to do, and packets might not be the best solution. Are you trying to make the broom kill itself when it is too fast, or is the broom currently killing itself when flown too fast (and you don't want that)?

That is why you should not be spoon-fed with tutorials without knowing what you are trying to accomplish.

It worked since the newer crash is not caused by the same cause. Update NEI. If the crash still occurs, report it to the author.

You are supposed to override Block#hasTIleEntity.

Remove Optifine and try again.

No you don't. Do not necro old thread; please make your own thread.

Please read the EAQ and post the appropriate log(s).

MCEdit?

You are removing the same iterator over and over again. That is not going to work. Read: https://www.tutorialspoint.com/java/java_using_iterator.htm I would use Collection#removeIf though.

You gonna pay for his plane ticket?

Remove Optifine and try again.

Please post a screenshot of your launcher and the versions dropdown menu.