Error fetching groups.java.lang.NullPointerException

Hi,
I have the problem with Datatype variable.
I created a datatype and I used it for 5 componente (same variables inside the PLCs) but I do not have the same results.
I do not see all variabiles and I have this error in the logs of Ignition: “Error fetching groups.java.lang.NullPointerException”

In the image below you can see the comportament.

Can you help me?

I use the OPC-UA protocol.

Please show the complete error with backtrace. Don’t use a screenshot. Instead, copy the text from the wrapper log and paste it here. Use triple backquotes (these: ```) on a line above and again below the pasted text so it will be formatted in a code block.

Also show the OPC Item Path for the affected tags.

This is the logs

Blockquote

Wrapper 19Mar2020 13:20:35 Error fetching groups.java.lang.NullPointerException
Wrapper 19Mar2020 13:20:35 Error fetching users.java.lang.NullPointerException
Wrapper 19Mar2020 13:19:16 Error fetching groups.java.lang.NullPointerException
Wrapper 19Mar2020 13:19:16 Error fetching users.java.lang.NullPointerException
Wrapper 19Mar2020 13:18:02 Error fetching groups.java.lang.NullPointerException
Wrapper 19Mar2020 13:18:02 Error fetching users.java.lang.NullPointerException
Wrapper 19Mar2020 13:16:50 Error fetching groups.java.lang.NullPointerException
Wrapper 19Mar2020 13:16:50 Error fetching users.java.lang.NullPointerException
Wrapper 19Mar2020 13:15:33 Error fetching groups.java.lang.NullPointerException
Wrapper 19Mar2020 13:15:33 Error fetching users.java.lang.NullPointerException
Wrapper 19Mar2020 13:14:18 Error fetching groups.java.lang.NullPointerException
Wrapper 19Mar2020 13:14:18 Error fetching users.java.lang.NullPointerException
Wrapper 19Mar2020 13:12:03 Error fetching groups.java.lang.NullPointerException
Wrapper 19Mar2020 13:12:03 Error fetching users.java.lang.NullPointerException

Blockquote

This is the variables path.

ns=6;s=::AsGlobalPV:Generatore[5].dig_inp.PressioneAria

I tried to create with this path a new OPC tag and this work.
You can see below

I do not understand why inside the datatype it do not work.

I don't think the error fetching groups/users is relevant. That looks like some other problem, happening every couple minutes or so.

I can't tell what's wrong with the affected elements of the UDT.... you'll have to carefully compare every property against the corresponding property of a working tag.

Consider exporting in XML format (one working, one non-working) and posting here as a code block. (Please use the triple back-quotes as requested--not the blockquote function.)

I found the problem. The Datatype variables do not support if you insert much OPC tags not defined inside it.
Now I defined all variables and it work.