diff --git a/packages/plugin/src/theia.d.ts b/packages/plugin/src/theia.d.ts
index a303dfe79ae76..1a0943bf0ada1 100644
--- a/packages/plugin/src/theia.d.ts
+++ b/packages/plugin/src/theia.d.ts
@@ -9702,7 +9702,7 @@ declare module '@theia/plugin' {
     }
 
     export enum TaskScope {
-        /** The task is a global task */
+        /** The task is a global task. Global tasks are currently not supported. */
         Global = 1,
 
         /** The task is a workspace task */
diff --git a/packages/task/src/browser/provided-task-configurations.ts b/packages/task/src/browser/provided-task-configurations.ts
index ad625a4287140..c35f2541efec5 100644
--- a/packages/task/src/browser/provided-task-configurations.ts
+++ b/packages/task/src/browser/provided-task-configurations.ts
@@ -17,7 +17,7 @@
 import { inject, injectable } from 'inversify';
 import { TaskProviderRegistry } from './task-contribution';
 import { TaskDefinitionRegistry } from './task-definition-registry';
-import { TaskConfiguration, TaskCustomization, TaskOutputPresentation, TaskConfigurationScope } from '../common';
+import { TaskConfiguration, TaskCustomization, TaskOutputPresentation, TaskConfigurationScope, TaskScope } from '../common';
 
 @injectable()
 export class ProvidedTaskConfigurations {
@@ -61,6 +61,8 @@ export class ProvidedTaskConfigurations {
             const providers = await this.taskProviderRegistry.getProviders();
             const providedTasks: TaskConfiguration[] = (await Promise.all(providers.map(p => p.provideTasks())))
                 .reduce((acc, taskArray) => acc.concat(taskArray), [])
+                // Global/User tasks from providers are not supported.
+                .filter(task => task.scope !== TaskScope.Global)
                 .map(providedTask => {
                     const originalPresentation = providedTask.presentation || {};
                     return {
@@ -116,12 +118,15 @@ export class ProvidedTaskConfigurations {
             }
         }
 
+        // Tasks with scope set to 'Workspace' can be customized in a workspace root, and will not match
+        // providers scope 'TaskScope.Workspace' unless specifically included as below.
+        const scopes = [scope, TaskScope.Workspace];
         // find the task that matches the `customization`.
         // The scenario where more than one match is found should not happen unless users manually enter multiple customizations for one type of task
         // If this does happen, return the first match
-        const matchedTask = matchedTasks.filter(t =>
-            scope === t._scope && definition.properties.all.every(p => t[p] === customization[p])
-        )[0];
+        const matchedTask = matchedTasks.find(t =>
+            scopes.some(scp => scp === t._scope) && definition.properties.all.every(p => t[p] === customization[p])
+        );
         return matchedTask;
     }
 
diff --git a/packages/task/src/browser/quick-open-task.ts b/packages/task/src/browser/quick-open-task.ts
index 69cc242c3ed37..c296c67052749 100644
--- a/packages/task/src/browser/quick-open-task.ts
+++ b/packages/task/src/browser/quick-open-task.ts
@@ -246,7 +246,7 @@ export class QuickOpenTask implements QuickOpenModel, QuickOpenHandler {
         if (this.workspaceService.opened) {
             const roots = await this.workspaceService.roots;
             scopes.push(...roots.map(rootStat => rootStat.resource.toString()));
-            if (this.workspaceService.saved) {
+            if (this.workspaceService.saved || groupedTasks.get(TaskScope.Workspace.toString())?.length) {
                 scopes.push(TaskScope.Workspace);
             }
         }
diff --git a/packages/task/src/browser/task-configurations.ts b/packages/task/src/browser/task-configurations.ts
index 925dd8cb7ed41..19d47ee290f31 100644
--- a/packages/task/src/browser/task-configurations.ts
+++ b/packages/task/src/browser/task-configurations.ts
@@ -302,12 +302,8 @@ export class TaskConfigurations implements Disposable {
     /** Adds given task to a config file and opens the file to provide ability to edit task configuration. */
     async configure(token: number, task: TaskConfiguration): Promise<void> {
         const scope = task._scope;
-        if (scope === TaskScope.Global || scope === TaskScope.Workspace) {
-            return this.taskConfigurationManager.openConfiguration(scope);
-        } else if (typeof scope !== 'string') {
-            console.error('Global task cannot be customized');
-            // TODO detected tasks of scope workspace or user could be customized in those preferences.
-            return;
+        if (scope === TaskScope.Global) {
+            return this.openUserTasks();
         }
 
         const workspace = this.workspaceService.workspace;
diff --git a/packages/task/src/browser/task-definition-registry.ts b/packages/task/src/browser/task-definition-registry.ts
index 26e7beb927a8b..370f3c9939946 100644
--- a/packages/task/src/browser/task-definition-registry.ts
+++ b/packages/task/src/browser/task-definition-registry.ts
@@ -114,8 +114,13 @@ export class TaskDefinitionRegistry {
         }
         const def = this.getDefinition(one);
         if (def) {
-            // scope is either a string or an enum value. Anyway...the must exactly match
-            return def.properties.all.every(p => p === 'type' || one[p] === other[p]) && one._scope === other._scope;
+            // scope is either a string or an enum value. Anyway...they must exactly match
+            // "_scope" may hold the Uri to the associated workspace whereas
+            // "scope" reflects the original TaskConfigurationScope as provided by plugins,
+            // Matching "_scope" or "scope" are both accepted in order to correlate provided task
+            // configurations (e.g. TaskScope.Workspace) against already configured tasks.
+            return def.properties.all.every(p => p === 'type' || one[p] === other[p])
+                && (one._scope === other._scope || one.scope === other.scope);
         }
         return one.label === other.label && one._source === other._source;
     }
diff --git a/packages/task/src/common/task-protocol.ts b/packages/task/src/common/task-protocol.ts
index 682f0668d5c98..383d649b2d0a6 100644
--- a/packages/task/src/common/task-protocol.ts
+++ b/packages/task/src/common/task-protocol.ts
@@ -149,8 +149,8 @@ export namespace TaskCustomization {
 }
 
 export enum TaskScope {
-    Workspace,
-    Global
+    Global = 1,
+    Workspace = 2
 }
 
 export type TaskConfigurationScope = string | TaskScope.Workspace | TaskScope.Global;
@@ -158,6 +158,7 @@ export type TaskConfigurationScope = string | TaskScope.Workspace | TaskScope.Gl
 export interface TaskConfiguration extends TaskCustomization {
     /** A label that uniquely identifies a task configuration per source */
     readonly label: string;
+    /** When a string type is used it represents an Uri to the associated workspace folder */
     readonly _scope: TaskConfigurationScope;
 }