ASP.NET "page has not been precompiled" after publishing

The file '/bla.aspx' has not been pre-compiled, and cannot be requested.

Yeah, thanks ASP.NET!  The site was most definitely pre-compiled.  This very un-useful error message has myriad causes, but for me, 8 wasted hours later, I discovered that at least this time, it was due to use of NTFS compression on my development computer.

Microsoft invented the NTFS compression scheme, so you'd think they knew how to make products that worked well with it..  Or at worst, give an error message clearly stating that use of NTFS compression is incompatible with whatever you're trying to do at the time.  But no, we get useless error messages like the above.

8 extra hours spent on a website deployment that should've only taken 30 to 60 minutes!  It was enough to have me seriously wondering whether I should join the band of happy Ruby On Rails developers!  But then I suspect they have their fair or unfair share of technology gripes too.

My main gripe is that this was what programming was like 20 years ago - extremely unhelpful error messages, things that should work but don't, and many hours and days of wasted time for no good reason.  It is the 21st century now.  We've made so much progress.  Programming is so much easier - by far - than it's ever been before.  But c'mon, we still have stupid problems like this?  Yes, I know, it's a major advance on how things were, but these vestiges of "the old way" have to go.

And as for the particular project I was working on : an extra full day of work for what should've been a simple deployment, might well have cost me a sale.  Not impressed!

If you've published your website using Microsoft Visual Studio .NET (VS.NET) and you chose the option to precompile, and yet are getting this "has not been pre-compiled" message on the server you deploy to, check to see whether any *.compiled files exist in the website's "bin" folder.  If not, then go back to your development machine, and ensure NTFS compression is disabled for the "obj" directory nested within the top-level website project directory - or whatever other location is hosting the files you're precompiling.

Here's hoping you don't lose 8 hours on this stupid bug!

And thanks to a commenter on this blog for helping me find the problem after many hours of searching.