Until recently the Cydia server has been the victim of some major issues due to an outage at Amazon EC2 (which primarily hosts the Cydia website and payement gateway).
The problems included issues with the management of hosted packages along with some other issues which prevented users from purchasing any apps or saving their SHSH blobs to the Cydia server.
Good news tells us that Cydia is back up and running smoothly after 86 hours downtime. This was revealed by Saurik, the creator of Cydia, through a tweet.
After 86 hours offline, Cydia is finally back! I’m eating some celebratory cake, and am looking forward to a night with >1.5 hours of sleep!
Moreover, the users will now able to install packages like they would do normally and without any errors. The payment gateway is back online which means that users will also be able to purchase apps and the SHSH blobs issue has been fixed too. Though personally we recommend iPhone users to update all their apps, fixes, debs from their respective repositories so there is no room for any mishap.