Debugging Dynamics 365 plugins is one of those skills nobody teaches you properly. You learn it the hard way, usually at half nine at night, staring at a generic "an error occurred" message with no stack trace and no idea which of your six registered steps actually threw it. I have lost more hours than I care to admit to this exact scenario, and most of them were avoidable.
The problem is not that Dynamics 365 makes debugging hard on purpose. It is that most developers reach for the same tool every time, usually a local debugger attached to the sandbox process, when that is often the slowest way to find the answer. There is a much better order to work through, and getting it right saves you the better part of a day on anything non trivial.
Start With the Plugin Trace Log, Not the Debugger
Before you touch a debugger, turn on plugin tracing and look at what is actually in there. Every exception, every custom trace statement you have written, and the execution time for each step is sitting in the Plugin Trace Log entity, and most developers barely glance at it before jumping straight to remote debugging.
Tracing costs you almost nothing to set up. A handful of tracingService.Trace() calls at the start and end of each meaningful block tells you exactly how far execution got before it fell over, without needing to reproduce the issue with a debugger attached at all. I make this the first step on every plugin bug I am handed, because it usually narrows the search from an entire solution down to a single method within a couple of minutes.
Turning Trace Logs Into Something You Can Actually Read
The default trace log view in Dynamics 365 is not built for comfortable reading, so I export the relevant records and search them properly rather than scrolling through a form. Filtering by correlation ID when you have several plugins firing off the same event is the single biggest time saver here, because it stops you reading through unrelated noise from steps that have nothing to do with your bug.
The Plugin Profiler Is Underused
The Plugin Registration Tool has a built in profiler that lets you capture a real execution against live data, then replay it locally against your actual code with a debugger attached from the very first line. Almost nobody uses it, which is a shame because it solves the single biggest problem with plugin debugging, which is getting a debugger attached at the exact right moment before the code you care about has already run.
You start a profiling session against a step, trigger the action in the live app once, and the tool captures the full execution context as a file. From that point you can replay it as many times as you like without touching the live environment again, which matters enormously when the bug only shows up with a specific combination of field values you do not want to keep recreating by hand.
Remote Debugging Still Has Its Place
Attaching a debugger to the sandbox worker process is not wrong, it is just usually the wrong first move. Once the trace log and the profiler have narrowed things down to a specific method and a specific set of inputs, remote debugging is genuinely useful for stepping through business logic that depends on state you cannot easily fake, like a live integration response or a complex hierarchy of related records.
The mistake I see most often is developers attaching the debugger cold, with no idea which step is actually misbehaving, then setting breakpoints across half the assembly and hoping one of them gets hit in a useful place. That is exactly the kind of guesswork that turns a twenty minute fix into an afternoon. Narrow the problem first, then debug.
Unit Tests Stop You Debugging the Same Bug Twice
Once you have actually fixed something, write a test for it. FakeXrmEasy lets you fake the Dataverse organisation service well enough to unit test plugin logic without a real environment at all, and it runs in seconds rather than the minutes a full deployment cycle takes. I resisted this for years, mostly out of laziness, and it is one of the changes I regret not making earlier on the client work I cover in my Dynamics 365 consulting engagements.
The value is not really in catching brand new bugs. It is in making sure the bug you just spent two hours tracking down never quietly comes back after the next round of changes, which happens far more often than most teams like to admit. A handful of well chosen tests around your trickiest plugin logic pays for itself the first time someone else on the team touches that code.
My Honest Take
The order matters more than the tools themselves. Trace logs first to narrow the search, the profiler to get a debugger attached at exactly the right moment, remote debugging once you actually know what you are looking for, and a test written the moment you understand the fix so you never have to solve it again. Skip the first two steps and you end up debugging blind, which is exactly how a straightforward plugin bug turns into a wasted evening.
None of this is complicated once you have the habit, and it is a much smaller investment than the time lost to guessing. If your team is still debugging plugins by trial and error, it is worth an hour showing everyone the profiler alone. I go into some of the wider performance issues this same discipline uncovers in my piece on Dynamics 365 performance problems, and the two go hand in hand more often than you would think.
