UI identity entities pagination returns 404 on page 2+

[alexandrust88]

Describe the bug

The Vault UI displays a "404 Not Found" error when navigating to page 2 (or subsequent pages) of identity entities listing, even though entities exist on those pages.

Error message:

404 Not Found
Sorry, we were unable to find any content at /vault/access/identity/entities?page=2.
Double check the url or go back home.

To Reproduce

Steps to reproduce the behavior:

1. Run Vault in dev mode:

docker run -d --name vault-test -p 8200:8200 \
  -e VAULT_DEV_ROOT_TOKEN_ID=root \
  -e VAULT_DEV_LISTEN_ADDRESS=0.0.0.0:8200 \
  --cap-add=IPC_LOCK hashicorp/vault:1.20.4

2. Create 500 entities:

export VAULT_ADDR=http://127.0.0.1:8200
export VAULT_TOKEN=root
for i in $(seq 1 500); do
  vault write identity/entity name="test-entity-$(printf '%03d' $i)"
done

3. Open Vault UI at http://127.0.0.1:8200/ui
4. Login with token root
5. Navigate to Access > Identity > Entities
6. Page 1 loads correctly showing first 100 entities
7. Click page 2 in pagination controls
8. See error: 404 Not Found

Expected behavior

Page 2 should display entities 101-200, page 3 should display entities 201-300, etc.

Environment

• Vault Server Version (retrieve with vault status): 1.20.4 / 1.20.4-ent
• Vault CLI Version (retrieve with vault version): 1.20.4
• Server Operating System/Architecture: linux/amd64 (Docker/Kubernetes)

Additional context

• Reproduction confirmed on both Vault OSS 1.20.4 and Vault Enterprise 1.20.4-ent
• Page 1 displays correctly with 100 entities
• Total entities confirmed via API: vault list identity/entity/id returns all 500 entities
• The URL /vault/access/identity/entities?page=2 appears in browser but returns 404
• Vault CLI and API work correctly - only UI pagination is broken
• Related issue: Same root cause as UI identity groups pagination returns 404 on page 2+ #31691 (identity groups pagination)

Likely cause: The Ember.js router for /vault/access/identity/entities doesn't properly handle the page query parameter, same as the groups endpoint.

Workaround

Use vault list identity/entity/id via CLI.

[bayanoj330-dev]

Hello

[heatherezell]

Closing as duplicate of #31691