I have seen several threads by users with this problem, but apparently no solutions have been posted except for re-jailbreaking (which often does not work) and just waiting for the issue to solve itself. The solution I am about to share I found online, but I have NO idea why it works...it worked for me, and I hope it works for everyone else. To clarify, this is about what the error looks like in Cydia: (x) Size mismatch Now the solution: Turn off WiFi temporarily. Then go to Settings--> General--> Network--> VPN--> Add VPN Configuration-->IPSec Here is the configuration (available openly on the web): Description: Hotspot Shield Server: 126.96.36.199 Account: j8adhk Password: j8adhk Use Certificate: off Group Name: hss Secret: hss Save the configuration, then turn VPN on. Finally, turn WiFi back on and reconnect to your network. The bar on the top left of your screen should say "VPN" next to the WiFi indicator. Depending on whether or not this solves the problem, you should now be able to go back to Cydia and install whatever had failed before, although it can load significantly slower. Also, if it hangs up, hit cancel and retry it. It can be a bit slow. After you are done in cydia, simply turn off VPN from settings until the next time. Again, this solved the problem I was having, I have no idea how.The problem could be due to multiple causes however and this might not work for you every time. Hope this helps.