[mato]

Hi Mike

Thanks for the quick reply - when checking Windows version when writing the original post I was surprised to find my Surface was still running 1903.  I've now done the 1909 feature update but the problem persists.  I've been messing around for the last hour (or two now I think!) trying to find a way to consistently replicate it as it's seemingly inconsistent.  I managed to replicate the issue three times in a row using this method, but subsequently not consistently:

Steps

1. Edit Song 1 - make a change (e.g. change the Tempos value) and click Cancel - click Save Changes when prompted.
   
2. Edit Song 2 - don't make any changes, click Cancel and then Save Changes when prompted. (Variation: also happened when pressing OK at this stage, difference being Step 4 is skipped)
   
3. Black screen.
   
4. Use Windows back button - it asks you again whether you want to save changes. If you click yes you get an error in bottom right (overlaying black screen) saying something like 'you must add one or more pages'
   
5. Use Windows back button - this time click Discard, and then click back again to exit the app.
   
6. Re-open app.
   
7. (Steps from here on happened twice in a row but not third time) Edit Song 1 - notice that in fields that had tags (Genre and Collection) the tags were now duplicated
   
8. Click OK 
   
9. Black screen.
   
10. Click Windows back button - exits app.
    
11. Re-open app.
    
12. Edit Song 1 - tags reverted to one in each field (no longer duplicated)
    

Something I also noticed (may or may not be related) regarding the cancel button:

1. Edit a song - click Cancel without making any changes - observe you're not prompted to Save as you made no changes.
   
2. Edit a song - make some changes, click Cancel - you are prompted to Save - click Save Changes.
   
3. Edit a song - click Cancel without making any changes - you are prompted to Save, even though you made no changes.
   
4. Step 3 behaviour continues until app is restarted
   

Another thing which I think happens (hard to tell for sure) is when initially clicking "Edit", there seems to be an increased delay/small stutter when opening the Edit Song screen on the occasions where I subsequently get a black screen after clicking OK/Cancel.

I'll give things another go tomorrow and see if I can find any other ways to replicate it, but thought I would post all the above in case you notice something in amongst my comments which might hint at the cause of the issue.

Thanks

Edit: added final comment about the Edit Song delay.