There wasn't sufficient space available in the page 0 of RAM to allocate when you select 23 sensors.
Hence you were getting the error.
This creates sufficient space in the page1 of RAM, and try to build the project.
You can try to review the other forum： Re: Smartsense 17button compile error
Thanks Ring for the response but if I set 08 in the stack page offset it's worse. I tried to get closer to the max value (0xFF) but this is not good for stack and RAM is not enough yet.
I think the CY8C21434B not support 23 buttons in SmartSense with automatic threshold setting mode.
Can you confirm this? or I'm doing something wrong
I will say sorry to you for ignoring some important information in your description.
Because I set the Threshold Setting Mode: Manual in the test project, so I give you previous suggestion.
Now I test it again, found that if configure the project like you says, the chip will lack ram resource.