I have deployed a website created by ExB Dev 1.2 on the web server. I registered the app in ArcGIS Enterprise 10.8.1 and added the clientId in config.json file but still getting the "client_id not specified" error. (I have secured services in the web application.)
I am using a web map which contains multiple secured map and feature services being hosted on our ArcGIS Enterprise. Our ArcGIS Eenterprise has been configured with SAML IDP (Azure AD group).
I have Map, Image, Embed,Filter and FeatureInfo widgets. The services is shared with specific Portal group (which is linked to enterprise AD group).
Some of the users don't get the error but some (including myself) will get it.
Sometimes the service worker doesn't properly identify that your config.json has changed and should be reloaded. For various reasons I sometimes get in a state where a config file has an empty value and deleting the cache from DevTools -> Application -> Clear Site Data does not fix the problem. I wish ESRI would build in a feature of ExB where the client ID would be pushed into the config.json upon download of the app. This would alleviate a big pain point.
You could, after populating clientId, delete the config.json file from the Network tab (se image), or with DevTools open, right click the refresh button an choose Empty Cache and Hard Reload.
If a bad config.json is cached on your clients and clearing the service worker cache as described here doesn't work....idk. It is a scary prospect.