Recently helped someone solve a similar problem. After several hours of struggle, the solution turned out to be:
1. Delete LDS Tools.
2. Restart the iPad.
3. Sign out of iCloud. (For instructions on how to do that, see: http://www.imore.com/how-sign-out-your- ... e-and-ipad
4. Look up "LDS Tools" in the App Store and install again.
5. Sign in using your LDS Account information.
6. Sign into iCloud, again.
Step 3 is the key. If you don't sign out of iCloud, every time you reinstall, it will reinstall the corrupted version of the app from your iCloud account. Signing out of iCloud forces your phone to get a fresh copy of the app.
I'm going to recommend that no one follow my original advice (quoted above). As you can see in the comments that follow my original post, including my own, signing out of iCloud and then signing back in results in you having to spend a whole lot of time recovering your device to how it was before, and it is a real pain in the neck. You should avoid doing it.
I also have a new idea of what the problem is. I think that the problem is that some sort or user information in the app that is stored on the device (something equivalent to a cookie on a web browser) gets corrupted. You want to force the app to delete that corrupted user information file and generate a new one.
Try this instead of my original suggestion:
Go to Settings > General > iPhone Storage, then scroll down until you see LDS Tools and tap on it. Tap "Delete App, This will delete the app and all related data from this iPhone. This action can't be undone." Then, reinstall the app and log in again.
I haven't tried this method yet, but I think that it will probably work. It won't mess-up anything outside of deleting this particular app, so it's much better than signing out of iCloud.