Hi folks, long time no see :-)

I've got a current client whose site I'm upgrading from 4.7.2. to 6.2.6. The upgrade itself has been successul, but a number of content pages are returning HTTP 200 with an empty (zero-byte) response.

Info on the project: 1) It's a legacy 4.7.2 site with webforms, however it's also running an ASP.NET MVC app side-by-side. umbracoSettings.config has templates/defaultRenderingEngine set to WebForms, and we've set up custom routing for the MVC app that lives side-by-side in the same directory (there's an entire repository pattern, whereby Save/Publish events serialize the node into a separate DB, and the MVC aspect has repository patterns to retrieve said data. Huge technical debt, basically, which we're addressing in the next 4-8 weeks by porting the bespoke MVC to SurfaceControllers; 2) We've managed to successfully upgrade the site to 6.2.6 so the backoffice works and most of both the MVC and webforms pages work just fine, with the exception of a couple. Hence my need for PDBs to diagnose the Umbraco pipeline to find out why my responses are empty. 3) I have progressively removed any and all HttpModules which I believe may be interfering with the request pipeline, with no such luck. Although I previously had an issue where AXD's (WebResource.axd and ScriptResource.axd) were retuning 200 codes but zero response body, which I fixed with a routes.IgnoreRoute() call from my Global.asax.cs.

So my questions are as follows: 1) In what order do I need to instantite routing? I currently have routes being manually added after the OnApplicationStarted event in my Global.asax.cs. 2) Does someone out there have the PDB's for Umbraco 6.2.6 so I can debug this direct from source? There are no log entries when trying to load the pages in question, they simply return HTTP 200 & zero HTML/content length.

Things I have tried: 1) Compiling Umbraco direct from source on the 6.2.6 release tag, but a number of Nuget packages Umbraco used to use are no longer available, thus breaking the build entirely. I don't want to have to produce a custom build and go off-codebase to get PDBs, just so I can diagnose why this issue is happening. 2) Added logging on the masterpage for the pages that turn up 200 with zero content - no log entries found either in the umbracoLog table or in the log4net text logs.

Thanks in advance,

Benjamin