Unity bug - Uncaught javascript exception in Pathfinder

English tech description down below:
Nederlands: Krijg een foutmelding bij het accepteren van mijn Pionier missie. Het gaat om een niet gevangen exceptie vanuit het spel.

How did the error manifest itself?
I had a mission in the pathfinder to buff a friend. I left my pathfinder missions open when visiting the friend's island.
I actually still had the screen from the pathfinder open while I was on the other island. This also seems a bug to me.

After returning to my own island the screen from the pathfinder missions became blank. I reopened the screen and there I had an updated version of my mission that I wanted to accept.
Clicking the check button, I got the error message.

Date and time - When did the problem occur?
When clicking the weekly boat and opening the menu.
18.30 26-7-2021 on Woestewoud

What did you do last?
See above, reopening pathfinder screen.

Did the problem occur more than once?
No I cannot reproduce it.

Have you already done the first steps? + Have you cleared your cache and cookies?
Yes cleared history and cookies yesterday.

Can you take a screenshot of it?
https://snipboard.io/ne0rYp.jpg
https://snipboard.io/QUrY13.jpg
https://snipboard.io/kYNR7d.jpg

Which operating system do you use?
Windows 10

Internet provider / Internet speed
Broadband ~100Mbs - speedtest

Internet access
LAN

Please attach Screenshots of the Dev Console. Please send Screenshots of the "Inspector" tab AND the "Console" tab.
(Press F12 in the browser while you experience the error)
did not show any data

Which browser AND browser version are you using?
Chrome - Versie 91.0.4472.164 (Officiële build) (64-bits)

Also, kindly add reproduction steps, and feel free to add any details you find relevant.
See above