Replace with 404 can't load page

System.ArgumentException: Empty path name is not legal. at System.IO.File.WriteAllText(String path, String contents) at Security.SecurityController_v2.LoadBuildTemplate() in E:\Root\_sites\Bletchley\root\Security\SecurityController_v2.cs:line 2364 at Security.SecurityController_v2.LoadTemplate() in E:\Root\_sites\Bletchley\root\Security\SecurityController_v2.cs:line 2197

RawUrl: [/index.html]
UrlReferrer: [direct]
Fingerprint: [unknown]
Host: [peershealth.com]
HostName: [RD00155DF7B8CF]
IPAddress: [3.235.22.210]
Method: [GET]
Localization: [en]
route_url: [index.html]
deviceprint: [c45a7c8d-f835-4fd2-87f4-b03efa0d6541]
jwt: [eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ0eXAiOiJwcmUiLCJzZXNzaW9uZ3VpZCI6ImM0NWE3YzhkLWY4MzUtNGZkMi04N2Y0LWIwM2VmYTBkNjU0MSIsIm5vbmNlIjoiMjAyMC0wNy0xMSAxNjoxNTozOS4yMjZaIn0=.VzlUVFYxc3J2b2pNYlBMM0U0ditiMWxXTGZzeEwvbzVvVURhTGhSNUpzQXgzS0twd1Z0djFWMmcwbDJTdXZKMFJHMHhaM1V1c2IrcVVNR2dnRTBDTVE9PQ==]
sessionguid: [c45a7c8d-f835-4fd2-87f4-b03efa0d6541]