Unigram 3.13.2635 crashes when pressing the "scheduled messages" button in "saved messages".
I'm not able to reproduce this issue, maybe this depends on the message you scheduled?
Ok. Steps to reproduce are:

I have a Surface Pro 5th edition with Windows 10 Pro 1909 build 18363.476.
I reproduced the bug and despite the app crash, I got the notification
Trying to open Scheduled saved messages makes the app crash on my end as well.
If it helps: I have 2 saved messages now: for 31.12.2019 and for 29.07.2020.
This is fixed in 3.13.2638
Most helpful comment
Ok. Steps to reproduce are:
I have a Surface Pro 5th edition with Windows 10 Pro 1909 build 18363.476.