The digital editions app won’t open an ACSM file.

Hi.

I'm trying to read an ebook that I downloaded on the Digital Editions app on my iPhone. I have done it before and the ACSM files have worked normally. Now for some reason when I try to open the downloaded ACSM file it throws me out of the app completely. I have tried re-installing the app and it didn't work. Also, for some reason, I can't delete the file from the app. Is the problem in the file itself or is there something else I could try?