Hi Poppy Wolf,
The message is caused by a Group Policy setting called "Limit profile size" which you can find through Local Group Policy Editor (GPEdit.msc) at User Configuration/Administrative Templates/System/User Profiles.
The application data which you can find at %userprofile%\appdata\roaming are files automatically created by the programs on your system. Hence, it would be normal for those files to be recreated as soon as you re-open the program which creates/handles those files.
If you are using an account connected to a domain, we suggest that you contact your IT administrator to check and adjust the settings for your profile size/storage limit and avoid the need to delete or move files from time to time. If you are the IT or administrator of your PC and would need further assistance regarding the Limit profile size Group Policy setting, we would suggest that you post your thread on the **TechNet Windows 10 IT Pro forums**to get help from other IT Professionals.
Please respond to this thread to let me know how the issue progresses. Similarly, if you have more questions, please inform me by replying to this post.