diff --git a/spring-boot/src/test/java/org/dcsa/conformance/frontend/SeleniumTestBase.java b/spring-boot/src/test/java/org/dcsa/conformance/frontend/SeleniumTestBase.java
index fbe17a62..d698fbcb 100644
--- a/spring-boot/src/test/java/org/dcsa/conformance/frontend/SeleniumTestBase.java
+++ b/spring-boot/src/test/java/org/dcsa/conformance/frontend/SeleniumTestBase.java
@@ -258,19 +258,27 @@ private void completeAction() {
   private void updateSandboxConfigBeforeStarting(SandboxConfig sandbox1, SandboxConfig sandbox2) {
     log.info("Updating both sandbox configs before starting");
     // Starts in the 2nd tab
-    driver.findElement(By.name("externalPartyUrlTextField")).sendKeys(sandbox1.sandboxUrl());
-    driver.findElement(By.name("externalPartyAuthHeaderNameTextField")).sendKeys(sandbox1.sandboxAuthHeaderName());
-    driver.findElement(By.name("externalPartyAuthHeaderValueTextField")).sendKeys(sandbox1.sandboxAuthHeaderValue());
-    driver.findElement(By.id("updateSandboxButton")).click();
+    if (sandbox1.sandboxUrl() != null) {
+      driver.findElement(By.name("externalPartyUrlTextField")).sendKeys(sandbox1.sandboxUrl());
+      driver.findElement(By.name("externalPartyAuthHeaderNameTextField")).sendKeys(sandbox1.sandboxAuthHeaderName());
+      driver.findElement(By.name("externalPartyAuthHeaderValueTextField")).sendKeys(sandbox1.sandboxAuthHeaderValue());
+      driver.findElement(By.cssSelector("[testId='updateSandboxButton']")).click();
+    } else {
+      driver.findElement(By.cssSelector("[testId='cancelUpdateSandboxButton']")).click();
+    }
     waitForUIReadiness();
     assertTrue(driver.findElement(By.className("pageTitle")).getText().startsWith("Sandbox: "));
 
     // Starts in the 1st tab
     switchToTab(0);
-    driver.findElement(By.name("externalPartyUrlTextField")).sendKeys(sandbox2.sandboxUrl());
-    driver.findElement(By.name("externalPartyAuthHeaderNameTextField")).sendKeys(sandbox2.sandboxAuthHeaderName());
-    driver.findElement(By.name("externalPartyAuthHeaderValueTextField")).sendKeys(sandbox2.sandboxAuthHeaderValue());
-    driver.findElement(By.id("updateSandboxButton")).click();
+    if (sandbox2.sandboxUrl() != null) {
+      driver.findElement(By.name("externalPartyUrlTextField")).sendKeys(sandbox2.sandboxUrl());
+      driver.findElement(By.name("externalPartyAuthHeaderNameTextField")).sendKeys(sandbox2.sandboxAuthHeaderName());
+      driver.findElement(By.name("externalPartyAuthHeaderValueTextField")).sendKeys(sandbox2.sandboxAuthHeaderValue());
+      driver.findElement(By.cssSelector("[testId='updateSandboxButton']")).click();
+    } else {
+      driver.findElement(By.cssSelector("[testId='cancelUpdateSandboxButton']")).click();
+    }
     waitForUIReadiness();
     assertTrue(driver.findElement(By.className("pageTitle")).getText().startsWith("Sandbox: "));
   }
@@ -320,10 +328,11 @@ SandboxConfig createSandBox(Standard standard, String version, String suiteName,
     driver.findElement(By.id("mat-input-0")).sendKeys(sandboxName);
     driver.findElement(By.id("createSandboxButton")).click();
 
-    wait.until(ExpectedConditions.visibilityOfElementLocated(By.id("sandboxUrlInput")));
-    String sandboxURL = driver.findElement(By.id("sandboxUrlInput")).getAttribute("value");
-    String sandboxAuthHeaderName = driver.findElement(By.id("sandboxAuthHeaderNameInput")).getAttribute("value");
-    String sandboxAuthHeaderValue = driver.findElement(By.id("sandboxAuthHeaderValueInput")).getAttribute("value");
+    wait.until(ExpectedConditions.visibilityOfElementLocated(By.cssSelector("[testId='sandboxNameInput']")));
+    boolean noSandboxUrlInput = driver.findElements(By.cssSelector("[testId='sandboxUrlInput']")).isEmpty();
+    String sandboxURL = noSandboxUrlInput ? null : driver.findElement(By.cssSelector("[testId='sandboxUrlInput']")).getAttribute("value");
+    String sandboxAuthHeaderName = noSandboxUrlInput ? null : driver.findElement(By.cssSelector("[testId='sandboxAuthHeaderNameInput']")).getAttribute("value");
+    String sandboxAuthHeaderValue = noSandboxUrlInput ? null : driver.findElement(By.cssSelector("[testId='sandboxAuthHeaderValueInput']")).getAttribute("value");
     return new SandboxConfig(
       null,
       sandboxName,
diff --git a/webui/src/app/pages/edit-sandbox/edit-sandbox.component.html b/webui/src/app/pages/edit-sandbox/edit-sandbox.component.html
index adc1d1a0..172c46b1 100644
--- a/webui/src/app/pages/edit-sandbox/edit-sandbox.component.html
+++ b/webui/src/app/pages/edit-sandbox/edit-sandbox.component.html
@@ -17,6 +17,7 @@
         <br/>
         <mat-form-field class="fullWidth">
           <input
+            testId="sandboxNameInput"
             matInput
             type="text"
             autocomplete="off"
@@ -39,6 +40,7 @@
         <div *ngFor="let method of endpointUriAndMethods.methods">
           <div class="paragraph">{{ method }} {{ endpointUriAndMethods.endpointUri }}</div>
           <input
+            testId="sandboxUrlInput"
             class="readOnlyInput"
             type="text"
             readonly="readonly"
@@ -59,7 +61,7 @@
         </div>
         <div class="paragraph">Sandbox authentication header name:</div>
         <input
-          id="sandboxAuthHeaderNameInput"
+          testId="sandboxAuthHeaderNameInput"
           class="readOnlyInput"
           type="text"
           readonly="readonly"
@@ -67,7 +69,7 @@
         />
         <div class="paragraph">Sandbox authentication header value:</div>
         <input
-          id="sandboxAuthHeaderValueInput"
+          testId="sandboxAuthHeaderValueInput"
           class="readOnlyInput"
           type="text"
           readonly="readonly"
@@ -88,7 +90,7 @@
         <div>
           <br/>
           <mat-form-field class="fullWidth">
-            <mat-label>Base URL for all your endpoints</mat-label>
+            <mat-label>Application endpoints base URL</mat-label>
             <input
               matInput
               type="text"
@@ -218,7 +220,7 @@
     <br/>
     <div>
       <button
-        id="updateSandboxButton"
+        testId="updateSandboxButton"
         mat-raised-button
         color="primary"
         type="submit"
@@ -229,6 +231,7 @@
       </button>
       &nbsp;
       <button
+        testId="cancelUpdateSandboxButton"
         mat-raised-button
         type="button"
         (click)="onCancel()"