Processing Failed

I’m very new to Cubase; I have the trial version of Elements 10 for Windows 10. I’m trying to use the time stretch function, but it’s not working for any audio files, be they imported or native. Instead of processing, I get an exclamation point that says “processing failed” when I mouse over it. I saw this issue also being reported in the topic I linked below, but they were attempting pitch shift, whereas I’m trying to stretch without pitch shifting (don’t know if it’s the same issue or not). Any help is appreciated.