Logix 5000 - SIZE Instruction Shows ??

I am using Studio 5000 version 28.00.

Using the SIZE instruction in ladder code to get the length of an array of tag structures. The instruction (attached) displays "??" below the Source field. I have never seen this allow the project to be verified before BUT it is verified, downloaded, and running in a controller just fine. The "FlockPacketDataHistory[0]" tag is a member of an array...the members are UDT structures.

Has anyone ever seen this before? What would cause this? Perhaps it is because it is an array of tag structures the software does not know what data to show for the Source? Seems like a software display glitch to me.

Also...tech support wanted me to clear the PC registry and blow away all of my user preferences. No thanks.

Nah, I wouldn't. You're fine as is.

As for what is causing this, I've seen it before on running systems with indirect indexes. But I'll admit that it probably shouldn't be happening here.

That's normal. I use the SIZE instruction quite often, and it always shows up with question marks, and always runs just fine.

Interesting. I have always used it in ST...I guess this is the first time I have used it in LD. Thanks for the confirmation.