URL Issue for the navigation

[ChristyShafack]

When opening a project to see its case study, if you want to switch to the index or about page on the navigation, the URL displayed there is wrong and doesn't exist. The error displayed is

Failed to load resource: the server responded with a status of 500 (Internal Server Error) index.js:260 Uncaught (in promise) TypeError: Cannot read properties of null (reading 'innerHTML') at App._callee$ (index.js:260:38) at tryCatch (main.js:6301:2404) at Generator._invoke (main.js:6301:1964) at Generator.next (main.js:6301:3255) at asyncGeneratorStep (main.js:6303:103) at _next (main.js:6305:194)

Typically it looks like this
[localhost:8080/case/index] [localhost:8080/case/about ]

both pages are read as projects.

Please any help with this will be greatly appreciated