ios 12.0 upgrade with Acrobat Reader 18.09.14

All of my OneDrive files were working fine a couple days ago, pulling them into my iPad Acrobat through "other locations".

After the Apple "upgrades" to ios 12.0,, Arrrggghhh!!! about 1/2 my files will not open, getting the message "Could not open "filexxx.pdf" due to an unknown error.  Please try again later." 

I've already updated Acrobat to 18.09.14 and that didn't fix it.

Craziest thing, maybe 1/2 of the 75 or so files open normally, the other 1/2 fault.  I went back to the masters and re-downloaded everything to OneDrive again, but no change in which ones open on the iPad and which ones don't.

Any fixes???