<p>I have a c# asp.net web app. Breakpoints in the database layer are no longer stopping execution but the breakpoints in the UI layer are still working okay. Can anyone hazard a guess why this might be happening?</p>

<p>I've checked all the usual suspects (Debug build is on for all projects) and recompiled all projects in solution...</p>

[{'answer_id': 60102, 'author': 'Iain Holder', 'author_id': 1122, 'author_profile': 'https://Stackoverflow.com/users/1122', 'pm_score': 0, 'selected': False, 'text': '<p>Have you tried deleting your bin directories before recompiling?</p>\n'}, {'answer_id': 60106, 'author': 'Tyler', 'author_id': 5642, 'author_profile': 'https://Stackoverflow.com/users/5642', 'pm_score': 1, 'selected': False, 'text': "<p>I would ensure that the UI layer is referencing the appropriate 'debug' .dll's. I'd also consider pressing <kbd>CTRL</kbd>+<kbd>ALT</kbd>+<kbd>U</kbd> (<code>Modules View</code>) when you're debugging to see if symbols are loaded for your BLL and DAL <code>.dlls</code>. If not then Visual Studio is unable to find <code>.PDBs</code> for that file.<br>\nAre debug files <code>.PDBs</code> in the same directory as the <code>.dlls</code> that are being referenced from the Modules window?</p>\n"}, {'answer_id': 60110, 'author': 'FlySwat', 'author_id': 1965, 'author_profile': 'https://Stackoverflow.com/users/1965', 'pm_score': 1, 'selected': False, 'text': "<ul>\n<li>Attach the debugger to ASP.NET process and click on the modules window. Ensure that debugging symbols are loaded for the assemblies you want to debug.</li>\n<li>Make sure the UI is referencing the debug assemblies, not release assemblies.</li>\n<li>Make sure the .PDB files are in the /bin/debug/ directory</li>\n<li>Make sure you rebuild the entire solution before attaching the debugger.</li>\n<li>If the data tier is in a seperate solution, add the project to the UI SLN (You don't need to add a reference, those should already be established or your code wouldn't compile), so that the debugger can pull up the full code.</li>\n</ul>\n"}, {'answer_id': 60117, 'author': 'Guy', 'author_id': 1463, 'author_profile': 'https://Stackoverflow.com/users/1463', 'pm_score': 1, 'selected': False, 'text': '<p>Thanks for the responses and ideas guys - I had already tried all of those or variations of them.</p>\n\n<p>I think that it must be a very subtle VS bug. A colleague suggested I make the function that I was trying to break on public (previously "undefined" so was implicitly private) and try again. I did this and the breakpoint started to get hit. I then removed the public keyword and the breakpoint continued to be hit. No idea why this solved it but it did.</p>\n\n<p>Thanks for you help!</p>\n'}, {'answer_id': 60127, 'author': 'Nick Randell', 'author_id': 5932, 'author_profile': 'https://Stackoverflow.com/users/5932', 'pm_score': 1, 'selected': False, 'text': "<p>A couple of suggestions.\nThe first one is to check the status of the breakpoint in the source line. Is it a solid red ball? If not, it generally indicates that the file in question isn't the one used for the build.\nSecondly - have a look at the modules view and see what module and symbols have been loaded. You may find it's not what you expect.</p>\n\n<p>As for why - I've no idea!</p>\n\n<p>Nick</p>\n"}, {'answer_id': 1234258, 'author': 'Jack Marchetti', 'author_id': 117658, 'author_profile': 'https://Stackoverflow.com/users/117658', 'pm_score': 0, 'selected': False, 'text': '<p>I had the same issue and kept thinking "what did I change in web.config" to potentially do this?</p>\n\n<pre><code>  &lt;location path="." inheritInChildApplications="false"&gt;\n</code></pre>\n\n<p>That was not allowing breakpoints to work for me.</p>\n'}]
['https://Stackoverflow.com/questions/60093', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/1463/']