Acrobat iPhone shuts down trying to open file

I frequently use Adobe Scan to create .pdf files and send them to Acrobat to fill/sign and/or send a copy via email.

Starting yesterday, the process works as usual until I try to open the file in Acrobat or send it out from Acrobat...Acrobat just closes without opening the file.

 I have updated my iPhone as well as the Adobe Scan and Acrobat, but it still keeps doing this!  
HELP PLEASE