Cannot edit the index setting as it shows an error said "Argument "coldPath_expanded" is not supported by this handler".
Splunk Enterprise version: 8.2.4
Since there is no such setting for indexes.conf there are two possible reasons.
1. Less likely - you have this setting set somewhere. Look for it with either find | grep or with splunk btool and remove
2. More likely - you hit some frontend issue and coldPath_expanded is a variable existing only on your browser's side for some strange reason. In such case it's probably a support case material.
@All-done-steak- Please check indexes.conf in the Splunk backend. There seems to be some issue with some config written in indexes.conf.
You can find indexes.conf files with find command in Linux:
find /opt/splunk -name "indexes.conf"
I hope this helps!!!