使用表视图委托时，为什么我会在索引超出范围时遇到致命错误？

I have two view controllers that both contain table views and I want it to where once a row is selected on the first table view, when it segues to the next table view the cells text's corresponds with whatever row they chose in the first table view. Imagine like the settings app, once you select on row, in the next view controller you are always presented the SAME cell text options for that corresponds with what you chose on the previous table view. I'm using a dictionary's keys and values and matched their index in the did select at row but when I run the code at runtime I get an error that says index out of range, anyone know why this is happening?I have two view controllers that both contain t