Please kindly help and support for this issue.
Welcome to the community, @sawhenrythein! Could you also let us know the KoboToolbox server and the browser you are using? This should help us troubleshoot your issue.
I’m using the Kobo Toolbox server is kc.kobotoolbox.org and Microsoft Edge browser. I was tried on Firfox browser but it happening same error.
Please kindly share and support if you can.
Thanks and really appreciate your kind support.
@sawhenrythein, maybe this post discussed previously should help you solve your issue:
If you still have issues, please feel free to reach us back.