I am using ArgGis 10.5.1. I am trying to use Points to Line tool but when I open it it automatically comes up with an X symbol in red next to input feature (I've attached a photo). I have tried inputting all the necessary data and pressing OK but it simply says error with a yellow triangle and ! inside it. I used this tool yesterday on the same data set and it worked without a problem. I have also tried closing out of Arcmap as well as restarting my computer. Any suggestions or advice would be very helpful!