Have you tried uploading the same in the KoBoToolbox server? I tried and did not get any error message. It should work smoothly at your end too.
Besides, if you are referring to the message you received while validating your xlsform here and saw something as below:
It’s simply an added note provided to you/users on
repeat group (which states that you will be able to see the first set of repeating questions by default as shown in the image below boxed with red highlight):
The note also provides you a way-out on how to make
0 repeats if there are no repeats while collecting data in the field. One of them is pressing the
- like highlighted red box as shown in the image above. On pressing the same you should receive a confirmation dialogue box as shown in the image below:
If you press CONFIRM, you would then see the data entry screen as shown below:
It note also provides you a link where you could learn more on
A screenshot of the same is shown here below (for your ease):
Have a great day!