When I try to add a new page, an error message appears: UncaughtPromiseError > TypeError Uncaught Promise > Failed to fetch TypeError: Failed to fetch at Object.get

(mydomain/web/assets/14c8bb2/web.assets_web.min.js:2874:92)at mydomain/web/assets/14c8bb2/web.assets_web.min.js:15966:49at AddPageDialog.getCssLinkEls (mydomain/web/assets/14c8bb2/web.assets_web.min.js:15967:91)at Object.getCssLinkEls (mydomain/web/assets/14c8bb2/web.assets_web.min.js:15962:727)at AddPageTemplates.preparePages (mydomain/web/assets/14c8bb2/web.assets_web.min.js:15957:37)at AddPageTemplates. (mydomain/web/assets/14c8bb2/web.assets_web.min.js:15956:653)at mydomain/web/assets/14c8bb2/web.assets_web.min.js:1005:80at Array.map ()at ComponentNode.initiateRender (mydomain/web/assets/14c8bb2/web.assets_web.min.js:1005:69)at mydomain/web/assets/14c8bb2/web.assets_web.min.js:1541:80

mydomain is a placeholder name used for example purposes. Do these messages indicate errors in the program installation?