This is something that stumped me fairly recently. It’s also something that I was trying to work out what I should use at the title for this post! Let me share what happened.

I’m working on a project that’s quite critical (COVID-19 related). This is a project that we’ve built something around Dynamics 365 as an additional wrapper, to provide specific functionality for the pandemic. It’s being rolled out (the same solution) to multiple clients, and is only using the functionality from Power Platform. No custom code at all.

Now, before going into the specifics around it, let’s take a moment to revisit what a lookup field is, and what it does. Essentially a lookup field connects two tables together (wow – that felt strange not to use the word ‘entity’!). In the front interface, it’s used for a 1:N relationship.

So for example, we can have a lookup from Account to Contact, to set the primary contact for the account. The user navigates to the field, searches for the record they’re wanting to associate, and saves it.

Underneath, there’s a relationship that’s automatically created between the two tables, showing the way that the relationship will go (ie 1:N or N:1). This is created on both sides (more on that another time around dependencies), and most people will never need to modify it

When I first started with this particular project, I got the solution, and deployed it into the Dev environment (for the project that I was on). On testing it out, I found something very interesting. We’re using the Case (Incident) table, and there are various lookup fields on it. One of these was already populated with a value. Hmm – that’s interesting, I thought. It was a new deployment, and we hadn’t set any static data up yet at all. So how could it already be populated?

Furthermore, I was unable to save the Case record. When I tried to, I was getting an interesting error:

On drilling down into the error log (which admittedly is actually getting better in the details shown in it, thankfully!), it turned out to be because I didn’t have access to the referenced record (in the lookup field). It just didn’t exist.

So the lookup field value was coming in with a hard-coded GUID (record identifier). But how was this being done, especially if there weren’t any records (of that type) in the system at all?

From my experience of things, I could think of two ways in which to populate a lookup field with a hard-coded value:

• Through a ‘real-time’ Power Automate flow, on create of the record. It’s possible to set a GUID value in the flow, and then it would be set
• Through custom code, running on the form. Again, it’s possible to hard-code a GUID there, and then set the field

However on checking both options, none of them were happening. No Power Automate flows touching the Case record, and no custom code at all on the Case.

It was then, digging through the other parts of the solution, that I saw various Business Rules. For those unfamiliar with these, I’ll quote from the official Microsoft documentation around them:

By combining conditions and actions, you can do any of the following with business rules:

• Set column values
• Clear column values
• Set column requirement levels
• Show or hide columns
• Enable or disable columns
• Validate data and show error messages
• Create business recommendations based on business intelligence.

I’ve used Business Rules (somewhat extensively) before. However on going into the one for the Case table, I found that something was happening that I wasn’t aware could happen! It’s actually possible to set a lookup field value through it:

Even though we’ve deployed the solution from the original development environment to a different environment, this is still set. But there are no records that are available:

I had never thought that it would be possible – to set a static value (eg a number, or some text), fine. But to set referential data? Wow.

Obviously this can be quite helpful. The bit that it’s NOT helpful though is when deploying the solution to another environment (as this situation was). It doesn’t help if you re-create the record that it’s referring to with using the same record name, as it’s using the underlying GUID (which you can’t re-create). This really does take solution deployment into a whole new perspective, where you need to be careful around these sorts of things as well.

So something new that I’ve learned (I do try to learn something new each day), and specifically around an area I thought I knew quite well. It did take some time, but I’m glad that I (finally) found the root cause of it, and identified what was causing it.

Have you ever had something like this happen, where you’re searching & searching for the cause of it? Drop a line below – I’d love to hear!