Red icon - and what to do about it

I have just got Nextcloud up and running on Raspberry Pi. It is working very well. I would like to know what to do about the red icon?
Perhaps nothing as syncing is running as it should?
Could I somewhere check a box telling Nextcloud “You found a name clash - but it is not a problem - please proceed”?
Is this the same problem as Dropbox writing “…conflicted copy with WindowsAtWorkComputer”? And if - should this feature then get into future releases of Nextcloud?
Text showing the problem here:
Nextcloud version 12.0.0
Operating System Windows 10 x64


Did you rename the file to avoid the name conflict. Some special characters are not allowed because some operating systems do not support them. Is this a NTFS formatted disk on your client?

I renamed the files. And yes it is a NTFS file system.
Upon renaming the files I got these outputs. But the files didn’t download to my folders.

Next screen shot:

I would expect a case sensitivity clash if you have files or folder which differ only in their case sensitivity. And that can lead to problems on some systems.

Thank you for your answer! Please tell if I can help in any way to improve the functionality of Nextcloud with my limited ressources of programming skills and knowledge of linux and php.

For normal users, the most helpful things is if they help to improve the documentation (points that are unclear or misleading) or the general behaviour of Nextcloud (unlogic interface, better error messages, …)