Getting stuck in the popup window

[Scowley4]

I'm not sure exactly what is causing it, but sometimes I get stuck in the popup window, with no way to exit.

I get just a single line >>> prompt at the bottom of the screen. I can type, but everything I type pops up a red error message:

Error detected while processing function <SNR>104_AcceptSelection[27]..ctrlp#acceptfile[42]..ctrlp#normcmd:
line   13:
E994: Not allowed in a popup window
Error detected while processing function <SNR>104_AcceptSelection[27]..ctrlp#acceptfile[52]..<SNR>104_openfile:
line    7:
E994: Not allowed in a popup window

Probably not a super helpful issue report -- hoping to add more information if I can find anything. Or if anyone has any suggestions of how to resolve the problem or at least exit the window, would be much appreciated. Right now, I'm just closing the whole terminal and reopening, which is not ideal.