Are there any real consequences of "No serializer found" in java?

Serializing with Jackson (JSON) - getting "No serializer found"? I was looking through these posts. And looks like this is a kind of warning and not a serious issue (People are talking about suppressing it, so that must not be very useful for tracing and debugging the program). I'm not a programmer FYI. But a system administrator who knows little bit of code.

org.codehaus.jackson.map.JsonMappingException: No serializer found for class MyPackage.TestA and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) This is exactly the error that I am getting. I work at a transaction doing app startup.

Firstly, make me understand what is this error trying to say? People say "lazy loading"...and stuffs. But as a sysadmin, make me understand this.

I've noticed this error is coming in both succeess and failed transactions. But successful transactions later succeed anyway. The only difference there seems is there is something called senderId being generated for success transactions and that value is being sent as NULL for failure transactions.

Help me with this issue.

I've tried reading all the posts and internet. I don't really want to understand the fix of this. It's written everywhere in internet. For instance

InvalidDefinitionException No serializer found in java for generic class

I want to understand the cause of this and effects of this from the first principles.

Solution

The real answer to your question ("Are there any real consequences?") can only be "It depends."

To help you understand the situation better I try to explain the lingo involved in a very basic way:

An object is data bundled with code to access the data - you are not supposed to access the objects data in memory in other ways than by the code of the object.
To save the object to disk, you just serialize it, that means you bring its data into a form that can be written to a file or sent over the network. Usually the code is not written or sent.
The opposite (read object from disk) you deserialize it.
Lazy loading means that you initialize / load / deserialize / calculate the data of an object the first time you actually need it. (Since you only access it via the provided code of the object, this code decides that.)
The opposite would be eager loading - means that on the start of the program or creation of the object you load / deserialize / calculate the data in the object.

The message you wrote ("No serializer found") means that it is unknown how to write the data of an object to disk or send it over the network. Depending on the desired function, this can be a big problem or no problem (when nothing actually should be written).

In some programs you can configure the method how to serialize from the outside (so the error message signals a wrong configuration), in other cases it's hardcoded in the program (so the error means that the programmers didn't test thoroughly or didn't care about the error). The message

no properties discovered to create BeanSerializer

signals that its probably the externally configurable variant, but without further documentation no guarantee for that.

On the other hand SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS usually is more likely to be hardcoded.

So without a piece of code that creates that error message I could not provide real solutions, but your question indicates that a solution is not your goal anyways.