diff --git a/docs/releases/v2.3.3.md b/docs/releases/v2.3.3.md
index 44895d219..ad662197a 100644
--- a/docs/releases/v2.3.3.md
+++ b/docs/releases/v2.3.3.md
@@ -1,5 +1,6 @@
-# v2.3.3
+# v2.3.2
 
 ## Bugfixes
 
-- fix bug where fetching of regional features does not complete for logged in users (#826). (the viewer will only fetch released datasets)
\ No newline at end of file
+- fix backwards compatibility with some URLs
+- fix bug where fetching of regional features does not complete for logged in users (#826). (the viewer will only fetch released datasets)
diff --git a/e2e/src/advanced/urlParsing.prod.e2e-spec.js b/e2e/src/advanced/urlParsing.prod.e2e-spec.js
index d9ba92944..4a95357e7 100644
--- a/e2e/src/advanced/urlParsing.prod.e2e-spec.js
+++ b/e2e/src/advanced/urlParsing.prod.e2e-spec.js
@@ -74,8 +74,23 @@ describe('> url parsing', () => {
     expect(red).toEqual(blue)
   })
 
+  it('> [bkwards compat] if ill defined labelIndex for regionsSelected are defined, should handle gracefully', async () => {
+    const url = '/?parcellationSelected=JuBrain+Cytoarchitectonic+Atlas&templateSelected=MNI+Colin+27&navigation=0_0_0_1__-0.2753947079181671_0.6631333827972412_-0.6360703706741333_0.2825356423854828__3000000__-17800000_-6700000_-7500000__200000&regionsSelected=142&niftiLayers=https%3A%2F%2Fneuroglancer.humanbrainproject.org%2Fprecomputed%2FJuBrain%2Fv2.2c%2FPMaps%2FBforebrain_4.nii'
+    await iavPage.goto(url)
+    await iavPage.clearAlerts()
+    await iavPage.wait(5000)
+    await iavPage.waitForAsync()
+    const log = await iavPage.getLog()
+    const filteredLog = log.filter(({ message }) => !/Access-Control-Allow-Origin/.test(message))
+
+    // expecting some errors in the console. In catastrophic event, there will most likely be looped errors (on each render cycle)
+    expect(
+      filteredLog.length
+    ).toBeLessThan(50)
+  })
+
   it('> if niftiLayers are defined, parcellation layer should be hidden', async () => {
-    const url = `/?templateSelected=MNI+152+ICBM+2009c+Nonlinear+Asymmetric&parcellationSelected=JuBrain+Cytoarchitectonic+Atlas&niftiLayers=https%3A%2F%2Fneuroglancer.humanbrainproject.eu%2Fprecomputed%2FJuBrain%2F17%2Ficbm152casym%2Fpmaps%2FVisual_hOc1_r_N10_nlin2MNI152ASYM2009C_2.4_publicP_a48ca5d938781ebaf1eaa25f59df74d0.nii.gz`
+    const url = `/?parcellationSelected=JuBrain+Cytoarchitectonic+Atlas&templateSelected=MNI+Colin+27&navigation=0_0_0_1__-0.2753947079181671_0.6631333827972412_-0.6360703706741333_0.2825356423854828__3000000__-17800000_-6700000_-7500000__200000&regionsSelected=142&niftiLayers=https%3A%2F%2Fneuroglancer.humanbrainproject.org%2Fprecomputed%2FJuBrain%2Fv2.2c%2FPMaps%2FBforebrain_4.nii`
     await iavPage.goto(url)
     await iavPage.clearAlerts()
 
@@ -149,4 +164,5 @@ describe('> url parsing', () => {
     expect(visibleArr.length).toEqual(3)
     expect(visibleArr).toEqual([true, true, true])
   })
+
 })
diff --git a/e2e/util/selenium/base.js b/e2e/util/selenium/base.js
index ffc990ab1..8a858a1eb 100644
--- a/e2e/util/selenium/base.js
+++ b/e2e/util/selenium/base.js
@@ -98,6 +98,11 @@ class WdBase{
     return result
   }
 
+  async getLog() {
+    const browserLog = await this._browser.manage().logs().get('browser')
+    return browserLog
+  }
+
   async getRgbAt({ position } = {}, cssSelector = null){
     if (!position) throw new Error(`position is required for getRgbAt`)
     const { x, y } = verifyPosition(position)
diff --git a/src/atlasViewer/atlasViewer.urlUtil.ts b/src/atlasViewer/atlasViewer.urlUtil.ts
index 59640205e..ec9bbeebf 100644
--- a/src/atlasViewer/atlasViewer.urlUtil.ts
+++ b/src/atlasViewer/atlasViewer.urlUtil.ts
@@ -145,7 +145,7 @@ const parseSearchParamForTemplateParcellationRegion = (searchparams: URLSearchPa
     const selectedRegionsParam = searchparams.get('regionsSelected')
     if (selectedRegionsParam) {
       const ids = selectedRegionsParam.split('_')
-      return ids.map(labelIndexId => getRegionFromlabelIndexId({ labelIndexId }))
+      return ids.map(labelIndexId => getRegionFromlabelIndexId({ labelIndexId })).filter(v => !!v)
     }
 
     const cRegionsSelectedParam = searchparams.get('cRegionsSelected')