reading Microsoft Docs SharePoint Development overview, I found a nice querystring parameter, really helpful when trying to debug issues related to web parts placed on the page: ?maintenancemode=true
Using this querystring parameter, you can find a Web part summary, Web part manifest and Web part data.
In the WebPart manifest tab you can find valuable informations if you are trying to figure out possible problems with a WebPart like:
- what version of the SharePoint Framework has the web part been built on
- which components of the SharePoint Framework does the web part use
Normal page view
Maintenance mode page view using ?maintenancemode=true
Hope it is useful 🙂