# Missing type id property '_type' (for POJO property 'items') in EHRBase

**Category:** [General Discussion](https://discourse.openehr.org/c/general-discussion/132)
**Created:** 2022-11-02 14:47 UTC
**Views:** 4161
**Replies:** 1
**URL:** https://discourse.openehr.org/t/missing-type-id-property-type-for-pojo-property-items-in-ehrbase/3125

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## Post #1 by @surfer

Hi,
I start  by saying that I already checked the similar "Missing type id property error in Ehrbase" . 

My couple template/composition is at this link:  https://easyupload.io/v3ufjy 

The template has been created with the free Archetype Designer. The composition is derived , through the example method, from the template.

 The composition can be posted successfully but it cannot be retrieved. 

The GET returns the error:
"error":"Bad Request","message":"DB inconsistency:java.lang.IllegalArgumentException: Could not resolve subtype of [simple type, class com.nedap.archie.rm.datastructures.Item]: missing type id property '_type' (for POJO property 'items')\n at  ...[].... [truncated 9757 chars]; line: 3, column: 8681] (through reference chain: com.nedap.archie.rm.composition.Composition[\"content\"]->java.util.ArrayList[0]->com.nedap.archie.rm.composition.Observation[\"protocol\"]->com.nedap.archie.rm.datastructures.ItemTree[\"items\"]->java.util.ArrayList[0]->com.nedap.archie.rm.datastructures.Cluster[\"items\"]->java.util.ArrayList[0])"
The error position could be useful if it pointed to the culprit of the problem but just gives a generic problem with items, but which items and what problem ? there are a lot of items in the template. 

Any idea of what is going wrong?

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## Post #2 by @surfer

Turned out that if I remove all _uid the composition is retrieved correctly as in " [Missing fields in uploaded composition](https://discourse.openehr.org/t/missing-fields-in-uploaded-composition/2925)"

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**Canonical:** https://discourse.openehr.org/t/missing-type-id-property-type-for-pojo-property-items-in-ehrbase/3125
**Original content:** https://discourse.openehr.org/t/missing-type-id-property-type-for-pojo-property-items-in-ehrbase/3125