diff --git a/docs/releases/v2.5.5.md b/docs/releases/v2.5.5.md
new file mode 100644
index 0000000000000000000000000000000000000000..cc33173305d0da142c2bf34b94b9926e1e123be1
--- /dev/null
+++ b/docs/releases/v2.5.5.md
@@ -0,0 +1,10 @@
+# v2.5.5
+
+## Feature
+
+- Added pre-release warning
+
+## Under the hood
+
+- Temporarily use up-to-date endpoint for MEBRAINS
+- Add fsaverage to checklist
diff --git a/e2e/checklist.md b/e2e/checklist.md
index 7577819cb3cf150a1fc8588a165c9224b57290c0..fbe5c5240c08d8f8a88760a51d278bb0325dc2b5 100644
--- a/e2e/checklist.md
+++ b/e2e/checklist.md
@@ -46,6 +46,11 @@
       - [ ] the navigation should be preserved
   - [ ] in big brain v2.9 (or latest)
     - [ ] high res hoc1, hoc2, hoc3, lam1-6 are visible
+    - [ ] pli dataset [link](https://siibra-explorer.apps.hbp.eu/staging/?templateSelected=Big+Brain+%28Histology%29&parcellationSelected=Grey%2FWhite+matter&cNavigation=0.0.0.-W000.._eCwg.2-FUe3._-s_W.2_evlu..7LIx..1uaTK.Bq5o~.lKmo~..NBW&previewingDatasetFiles=%5B%7B%22datasetId%22%3A%22minds%2Fcore%2Fdataset%2Fv1.0.0%2Fb08a7dbc-7c75-4ce7-905b-690b2b1e8957%22%2C%22filename%22%3A%22Overlay+of+data+modalities%22%7D%5D)
+      - [ ] redirects fine
+      - [ ] shows fine
+  - [ ] fsaverage
+    - [ ] can be loaded & visible
 - [ ] Waxholm
   - [ ] v4 are visible
   - [ ] on hover, show correct region name(s)
\ No newline at end of file
diff --git a/mkdocs.yml b/mkdocs.yml
index 476dfab49e8293f4cb00942adf79868386926570..f518f97c0be45a63b2ca5579a32b335108810fd3 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -40,6 +40,7 @@ pages:
     - Fetching datasets: 'advanced/datasets.md'
     - Display non-atlas volumes: 'advanced/otherVolumes.md'
   - Release notes:
+    - v2.5.5: 'releases/v2.5.5.md'
     - v2.5.4: 'releases/v2.5.4.md'
     - v2.5.3: 'releases/v2.5.3.md'
     - v2.5.2: 'releases/v2.5.2.md'
diff --git a/package.json b/package.json
index 0f3aae01c1446f0e95a11d8265e25f925317d8d3..f84133d130a8f7ee46363b06b3036ebfcf72393b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "interactive-viewer",
-  "version": "2.5.4",
+  "version": "2.5.5",
   "description": "HBP interactive atlas viewer. Integrating KG query, dataset previews & more. Based on humanbrainproject/nehuba & google/neuroglancer. Built with angular",
   "scripts": {
     "build-aot": "VERSION=`node -e 'console.log(require(\"./package.json\").version)'` ng build && node ./third_party/matomo/processMatomo.js",
diff --git a/src/components/confirmDialog/confirmDialog.component.ts b/src/components/confirmDialog/confirmDialog.component.ts
index ec2e20c9fb6469c9ec26f88c77b73f50a77c57d3..8361ee409762ebccccfb6ae9c85d064207587dfc 100644
--- a/src/components/confirmDialog/confirmDialog.component.ts
+++ b/src/components/confirmDialog/confirmDialog.component.ts
@@ -25,15 +25,19 @@ export class ConfirmDialogComponent {
   @Input()
   public markdown: string
 
+  @Input()
+  public confirmOnly: boolean = false
+
   public hideActionBar = false
 
   constructor(@Inject(MAT_DIALOG_DATA) data: any) {
-    const { title = null, message  = null, markdown, okBtnText, cancelBtnText, hideActionBar} = data || {}
+    const { title = null, message  = null, markdown, okBtnText, cancelBtnText, hideActionBar, confirmOnly} = data || {}
     if (title) this.title = title
     if (message) this.message = message
     if (markdown) this.markdown = markdown
     if (okBtnText) this.okBtnText = okBtnText
     if (cancelBtnText) this.cancelBtnText = cancelBtnText
     if (hideActionBar) this.hideActionBar = hideActionBar
+    if (confirmOnly) this.confirmOnly = confirmOnly
   }
 }
diff --git a/src/components/confirmDialog/confirmDialog.template.html b/src/components/confirmDialog/confirmDialog.template.html
index f5f0549460e034215176f4393e3ea2507c83533d..8b8a0224a96105f7b475cfc587d2a25d11932b23 100644
--- a/src/components/confirmDialog/confirmDialog.template.html
+++ b/src/components/confirmDialog/confirmDialog.template.html
@@ -18,6 +18,6 @@
 <mat-divider></mat-divider>
 
 <mat-dialog-actions *ngIf="!hideActionBar" class="justify-content-start flex-row-reverse">
-    <button [mat-dialog-close]="true" mat-raised-button color="primary">{{ okBtnText }}</button>
-  <button [mat-dialog-close]="false" mat-button>{{ cancelBtnText }}</button>
+  <button [mat-dialog-close]="true" mat-raised-button color="primary">{{ okBtnText }}</button>
+  <button *ngIf="!confirmOnly" [mat-dialog-close]="false" mat-button>{{ cancelBtnText }}</button>
 </mat-dialog-actions>
diff --git a/src/services/dialogService.service.ts b/src/services/dialogService.service.ts
index eb0844dd7f3102b921fbe30de7a21a86280fe577..933b862275ca6838deb4ebabec3768ff604e4769 100644
--- a/src/services/dialogService.service.ts
+++ b/src/services/dialogService.service.ts
@@ -82,4 +82,5 @@ export interface DialogConfig {
   message: string
   markdown?: string
   iconClass: string
+  confirmOnly: boolean
 }
diff --git a/src/util/pureConstant.service.ts b/src/util/pureConstant.service.ts
index 609ebb9c43dcc51142a12a55783077a1cf65c392..22ab44b8c6b69b75b4aed5659a685f8d63bf9458 100644
--- a/src/util/pureConstant.service.ts
+++ b/src/util/pureConstant.service.ts
@@ -17,7 +17,7 @@ import { MatSnackBar } from "@angular/material/snack-bar";
 import { TTemplateImage } from "./interfaces";
 
 export const SIIBRA_API_VERSION_HEADER_KEY='x-siibra-api-version'
-export const SIIBRA_API_VERSION = '0.1.5'
+export const SIIBRA_API_VERSION = '0.1.6'
 
 const validVolumeType = new Set([
   'neuroglancer/precomputed',
@@ -577,25 +577,6 @@ Raise/track issues at github repo: <a target = "_blank" href = "${this.repoUrl}"
                                   ? 'right hemisphere'
                                   : 'whole brain'
 
-                              /**
-                               * TODO fix in siibra-api
-                               */
-                              if (
-                                tmpl.id !== 'minds/core/referencespace/v1.0.0/a1655b99-82f1-420f-a3c2-fe80fd4c8588'
-                                && parc.id === 'minds/core/parcellationatlas/v1.0.0/94c1125b-b87e-45e4-901c-00daee7f2579-290'
-                                && hemisphereKey === 'whole brain'
-                              ) {
-                                region.labelIndex = null
-                                return
-                              }
-
-                              if (
-                                tmpl.id === 'minds/core/referencespace/v1.0.0/a1655b99-82f1-420f-a3c2-fe80fd4c8588'
-                                && parc.id === 'minds/core/parcellationatlas/v1.0.0/94c1125b-b87e-45e4-901c-00daee7f2579-290'
-                                && hemisphereKey === 'whole brain'
-                              ) {
-                                region.children = []
-                              }
                               if (!region['ngId']) {
                                 const hemispheredNgId = getNgId(atlas['@id'], tmpl.id, parc.id, hemisphereKey)
                                 region['ngId'] = hemispheredNgId
@@ -751,12 +732,15 @@ Raise/track issues at github repo: <a target = "_blank" href = "${this.repoUrl}"
               const precomputedArr = tmpl._dataset_specs.filter(src => src['@type'] === 'fzj/tmp/volume_type/v0.0.1' && src.volume_type === 'neuroglancer/precomputed') as TVolumeSrc<'neuroglancer/precomputed'>[]
               let visible = true
               let tmplNgId: string
-              let templateImages: TTemplateImage[] = []
+              const templateImages: TTemplateImage[] = []
               for (const precomputedItem of precomputedArr) {
                 const ngIdKey = MultiDimMap.GetKey(precomputedItem["@id"])
+                const precomputedUrl = 'https://neuroglancer.humanbrainproject.eu/precomputed/data-repo-ng-bot/20211001-mebrain/precomputed/images/MEBRAINS_T1.masked' === precomputedItem.url
+                  ? 'https://neuroglancer.humanbrainproject.eu/precomputed/data-repo-ng-bot/20211018-mebrains-masked-templates/precomputed/images/MEBRAINS_T1_masked'
+                  : precomputedItem.url
                 initialLayers[ngIdKey] = {
                   type: "image",
-                  source: `precomputed://${precomputedItem.url}`,
+                  source: `precomputed://${precomputedUrl}`,
                   transform: precomputedItem.detail['neuroglancer/precomputed'].transform,
                   visible
                 }
diff --git a/src/viewerModule/viewerCmp/viewerCmp.component.ts b/src/viewerModule/viewerCmp/viewerCmp.component.ts
index bb0c20a548bf82504019a4fe307c180d6d498d4b..27c6eac25d510299e06a38c8e5be1814acb3d8c7 100644
--- a/src/viewerModule/viewerCmp/viewerCmp.component.ts
+++ b/src/viewerModule/viewerCmp/viewerCmp.component.ts
@@ -1,10 +1,11 @@
 import { Component, ComponentFactory, ComponentFactoryResolver, ElementRef, Inject, Injector, Input, OnDestroy, Optional, TemplateRef, ViewChild, ViewContainerRef } from "@angular/core";
 import { select, Store } from "@ngrx/store";
 import {combineLatest, merge, NEVER, Observable, of, Subject, Subscription} from "rxjs";
-import {catchError, distinctUntilChanged, filter, map, shareReplay, startWith, switchMap } from "rxjs/operators";
+import {catchError, debounceTime, distinctUntilChanged, filter, map, shareReplay, startWith, switchMap } from "rxjs/operators";
 import { viewerStateSetSelectedRegions } from "src/services/state/viewerState/actions";
 import {
   viewerStateContextedSelectedRegionsSelector,
+  viewerStateGetSelectedAtlas,
   viewerStateSelectedParcellationSelector,
   viewerStateSelectedTemplateSelector,
   viewerStateStandAloneVolumes,
@@ -25,6 +26,7 @@ import { MAT_DIALOG_DATA } from "@angular/material/dialog";
 import { GenericInfoCmp } from "src/atlasComponents/regionalFeatures/bsFeatures/genericInfo";
 import { _PLI_VOLUME_INJ_TOKEN, _TPLIVal } from "src/glue";
 import { uiActionSetPreviewingDatasetFiles } from "src/services/state/uiState.store.helper";
+import { DialogService } from "src/services/dialogService.service";
 
 type TCStoreViewerCmp = {
   overlaySideNav: any
@@ -112,7 +114,8 @@ export function ROIFactory(store: Store<any>, svc: PureContantService){
       },
       deps: [ ComponentStore ]
     },
-    ComponentStore
+    ComponentStore,
+    DialogService
   ]
 })
 
@@ -234,6 +237,7 @@ export class ViewerCmp implements OnDestroy {
     private viewerModuleSvc: ContextMenuService<TContextArg<'threeSurfer' | 'nehuba'>>,
     private cStore: ComponentStore<TCStoreViewerCmp>,
     cfr: ComponentFactoryResolver,
+    private dialogSvc: DialogService,
     @Optional() @Inject(_PLI_VOLUME_INJ_TOKEN) private _pliVol$: Observable<_TPLIVal[]>,
     @Optional() @Inject(REGION_OF_INTEREST) public regionOfInterest$: Observable<any>
   ){
@@ -271,7 +275,45 @@ export class ViewerCmp implements OnDestroy {
             ? getGetRegionFromLabelIndexId({ parcellation: p })
             : null
         }
-      )
+      ),
+      combineLatest([
+        this.templateSelected$,
+        this.parcellationSelected$,
+        this.store$.pipe(
+          select(viewerStateGetSelectedAtlas)
+        )
+      ]).pipe(
+        debounceTime(160)
+      ).subscribe(async ([tmpl, parc, atlas]) => {
+        const regex = /pre.?release/i
+        const checkPrerelease = (obj: any) => {
+          if (obj?.name) return regex.test(obj.name)
+          return false
+        }
+        const message: string[] = []
+        if (checkPrerelease(atlas)) {
+          message.push(`- _${atlas.name}_`)
+        }
+        if (checkPrerelease(tmpl)) {
+          message.push(`- _${tmpl.name}_`)
+        }
+        if (checkPrerelease(parc)) {
+          message.push(`- _${parc.name}_`)
+        }
+        if (message.length > 0) {
+          message.unshift(`The following have been tagged pre-release, and may be updated frequently:`)
+          try {
+            await this.dialogSvc.getUserConfirm({
+              title: `Pre-release warning`,
+              markdown: message.join('\n\n'),
+              confirmOnly: true
+            })
+          // eslint-disable-next-line @typescript-eslint/no-empty
+          } catch (e) {
+
+          }
+        }
+      })
     )
   }