Yindar

Its in the techniccache folder. Type %appdata% in the run box, then select the .technic folder, you should then find the cache folder. Delete everything in this folder.

Uninstall all Java, and install the latest

Make sure there are no old versions of java on your system. Also you can check "java -version" and make sure it pulls the 7.21. Check video drivers and .net are up to date. Other things to try, run in admin mode, with av disabled, and firewall down.

Clear the Cache files and try. Also if the launcher loads up, and lets you launch a pack, it could be a config issue with the pack.

Try deleting the cache

start..run..cmd.. \java -version Also edit your original post with the error log please, and what pack your trying to start.

So either there server overloaded, or your connection. Glad it started working!

You might be able to just delete everything out of the cache folder.

Can you start a new one, and does it edit and save?

So I found a fix, your going to love this. I downloaded someone else pack, made sure it worked (or at least unzipped). Then I deleted everything out of the zip and put my folders in its place. Then I renamed the zip and uploaded it to drop box. Ran the technic launcher and the mod pack worked just fine. So the problem was the zip file itself that was made with winzip. Go figgure....

I know nothing about MAC, however I do fix the problem on PC by deleting the Cache.

I don't think its a launcher problem. Looks more like a mod problem. Does it do this on all mods?

Make sure you have the latest video drivers, and flush the cache. In the Technic folder\cache\delete *.*

Unable to connect Running Offline. Firewall, Antivirus, run as admin

Update Java.. I was able to download the pack, and it installed, but does not work. Also I noticed there are no coremods in the pack (not sure if this one needs it). However the FML is not loading when minecraft starts, so the modpack.jar might not be right.

Try uninstalling all Java, reboot then install java.

Could it be a firewall blocking connection?

Under bug reports you can find the pack your running and look there for solutions. There are many things in game that can cause lag, depending on what pack your running.

c:\java -version

Need Error logs, correct launcher version, and java versions.

Uninstall everything including java, and delete the tekkit folders.. Reinstall java and download the latest launcher.

Also update your java

Uninstall everything, including all Java. Reinstall Java, then download Tekkit again. Run in adamin mod and without av on.

Uninstall all Java from your system and do a fresh install.

I would say, delete and reinstall.