I fixed this same error without reinstalling cydia
What I did was I downlaoded IExplorer. I wish I could post a link but it will not let me. So just google Iexplorer and its from
macroplant. I then installed it. It needs .net if you do not have it installed.
Then I connected my ipad to the computer. I then opened up IExplorer and told it to just use the demo.
In IExplorer it showed my Ipad I then clicked on
Files. Then I clicked on
Root it told me a message about to make sure you know what your doing I told it to continue. I then went through these folders
/etc/apt/sources.list.d/ and found
saurik.list.
I dragged and dropped
saurik.list to my desktop opened it with notepad. I deleted everything in it. Mine only had one line that said 'libpcreposix..0.0.0.dylib'. I removed it so it was blank. I then dragged and dropped it back onto the phone. It asked to replace I said OK.
I then fired up cyida and it worked. Hope this fix works for others instead of having to rejailbreak your device.