If I were still using iOS, I would remove the app, download it again, and then sync the data before I tried to do anything else. Then I would close the app.
I would restart the app, and I would sync the data again. Then I would try to use the app.
Throughout my history of using LDS Tools on iOS, I found that things did not normally work the first time. Whether I unfairly attributed it to programming error, it was reality for me.
I often found, however, that if I just did some things twice, they worked the second time. It was that way for me when the pass code was first required.
Every now and then, one of the developers is brave enough to show up here and confess to what is really happening. I am sure they like to have a fix in work before they do. (You know, something about shooting the messenger.)
But this upgrade has so many reported problems, that it would be nice to have some sort of idea what is going on.
The only thing worse than not having LDS Tools working is when LDS.org is also goofing up at the same time.
There was a way to get an old .ipa file back onto my iPod Touch if it was still in the Trash Bin and I moved it back into the iTunes area of my computer, then made sure I never accepted an update again. But it has been a long time since I did that, and I do not know if it works any longer.