I don’t have a full answer for you but the following may be helpful to relieve your obvious stress about whether your data is lost AND help you read your notes without using your iPAD.
The first thing you should do is secure whatever data you have in your Cloud account(s) or on your Mac (assuming you have one) to make sure it does not get damaged from here on.
IF you back up to the Cloud then the first thing you should do is make a copy of the files you have in your cloud storage environment relating to NotesPlus ( whether its iCloud or DropBox ).
This will secure whatever data you have.
If you are backing up to iCloud, then there will be a copy of the iCloud files on your Mac (if you have one).
If you do have a Mac then go to your iCloud directory in ~/Library/Mobile Documents and find the directory that relates to NotesPlus backups and make a copy of it on your Mac local disk.
This will secure your current data on your Mac.
If you do have a Mac and you also have a Time Machine backup of your Mac then the Time Machine backup should have historical copies of your notes.
If you do then make sure you keep this backup disk safe and sound.
Because Time Machine drops old backups off as the disk fills up with more recent backups, make sure you don’t let that happen.
STEP #4 - INSPECTING YOUR CLOUD DATA
Use Finder to look at the contents of the NotesPlus backup folders.
What you should see is a folder structure that looks like your NotesPlus library.
If NotesPlus has done the npn file migration you will see “package” files like:
You can open these package .npn files and view their contents as follows:
Open the Terminal application on your Mac.
Navigate to the folder holding your NotesPlus backups:
Pick on an .npn package file ( eg in the example below Prolog.npn )
The change directory into the package file:
USER@MAC Notebooks % cd Prolog.npn
USER@MAC Prolog.npn %
Now list the contents of the package file:
USER@MAC Prolog.npn % ls -l -R
drwxr-xr-x 6 USER staff 192 11 Aug 00:22 1
-rw-r----- 1 USER staff 250 18 Sep 2019 index.html
-rw-r-----@ 1 USER staff 448 11 Aug 00:22 notebook.xml
-rw-r-----@ 1 USER staff 124 11 Aug 00:22 notebookInfo.js
drwxr-xr-x 2 USER staff 64 11 Aug 00:22 resources
-rw-r-----@ 1 USER staff 725 18 Sep 2019 index.html
-rw-r-----@ 1 USER staff 73 18 Sep 2019 meta.xml
-rw-r-----@ 1 USER staff 145630 10 Aug 13:54 page.svg
drwxr-xr-x 3 USER staff 96 11 Aug 00:22 resources
-rw-r----- 1 USER staff 27923 10 Aug 13:54 thumbnail.png
USER@MAC Prolog.npn %
If you can see the files called page.svg then you have your handwritten notes.
All is probably not lost.
See the following post about how to use Finder to open a package file on MacOS ( it’s easier ).
In terms of how to fix things up on your iPad … you’ll have to wait for help from those in the know.
READING YOUR NOTES WITHOUT USING AN IPAD
Fortunately, you can read the contents of the npn file in a web browser ( this is the single BEST feature of NotesPlus meaning your handwriting is NOT locked up in a proprietary binary format ).
To do this it helps to copy the contents of the .npn file out into a normal directory on your Mac then you can just use Safari to open the index.html file and voila you should be able see your notes page by page.
PS - If you’re not a computer techie person, you might want to get a friend to help you salvage your notes.
PPS - If you want to talk reach out with some contact details eg Skype / Zoom ( New Zealand time )