diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/workspace.tasks.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/workspace.tasks.test.ts
index 0bd491abd0b..4ec107c23be 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/workspace.tasks.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/workspace.tasks.test.ts
@@ -4,7 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import * as assert from 'assert';
-import { window, tasks, Disposable, TaskDefinition, Task, EventEmitter, CustomExecution, Pseudoterminal, TaskScope, commands, Task2, env, UIKind, ShellExecution, TaskExecution, Terminal } from 'vscode';
+import { window, tasks, Disposable, TaskDefinition, Task, EventEmitter, CustomExecution, Pseudoterminal, TaskScope, commands, Task2, env, UIKind, ShellExecution, TaskExecution, Terminal, Event } from 'vscode';
 
 // Disable tasks tests:
 // - Web https://github.com/microsoft/vscode/issues/90528
@@ -220,5 +220,54 @@ import { window, tasks, Disposable, TaskDefinition, Task, EventEmitter, CustomEx
 				taskExecution = await tasks.executeTask(task);
 			});
 		});
+
+		// https://github.com/microsoft/vscode/issues/100577
+		test('A CustomExecution task can be fetched and executed', () => {
+			return new Promise(async (resolve, reject) => {
+				class CustomTerminal implements Pseudoterminal {
+					private readonly writeEmitter = new EventEmitter<string>();
+					public readonly onDidWrite: Event<string> = this.writeEmitter.event;
+					public async close(): Promise<void> { }
+					public open(): void {
+						this.close();
+						resolve();
+					}
+				}
+
+				function buildTask(): Task {
+					const task = new Task(
+						{
+							type: 'customTesting',
+						},
+						TaskScope.Workspace,
+						'Test Task',
+						'customTesting',
+						new CustomExecution(
+							async (): Promise<Pseudoterminal> => {
+								return new CustomTerminal();
+							}
+						)
+					);
+					return task;
+				}
+
+				disposables.push(tasks.registerTaskProvider('customTesting', {
+					provideTasks: () => {
+						return [buildTask()];
+					},
+					resolveTask(_task: Task): undefined {
+						return undefined;
+					}
+				}));
+
+				const task = await tasks.fetchTasks({ type: 'customTesting' });
+
+				if (task && task.length > 0) {
+					await tasks.executeTask(task[0]);
+				} else {
+					reject('fetched task can\'t be undefined');
+				}
+			});
+		});
 	});
 });
diff --git a/src/vs/workbench/api/browser/mainThreadTask.ts b/src/vs/workbench/api/browser/mainThreadTask.ts
index 8b37ab49c14..a51b71d9fb2 100644
--- a/src/vs/workbench/api/browser/mainThreadTask.ts
+++ b/src/vs/workbench/api/browser/mainThreadTask.ts
@@ -328,10 +328,10 @@ namespace TaskDTO {
 			result.detail = task.configurationProperties.detail;
 		}
 		if (!ConfiguringTask.is(task) && task.command) {
-			if (task.command.runtime === RuntimeType.Process) {
-				result.execution = ProcessExecutionDTO.from(task.command);
-			} else if (task.command.runtime === RuntimeType.Shell) {
-				result.execution = ShellExecutionDTO.from(task.command);
+			switch (task.command.runtime) {
+				case RuntimeType.Process: result.execution = ProcessExecutionDTO.from(task.command); break;
+				case RuntimeType.Shell: result.execution = ShellExecutionDTO.from(task.command); break;
+				case RuntimeType.CustomExecution: result.execution = CustomExecutionDTO.from(task.command); break;
 			}
 		}
 		if (task.configurationProperties.problemMatchers) {
diff --git a/src/vs/workbench/api/node/extHostTask.ts b/src/vs/workbench/api/node/extHostTask.ts
index b785156b037..37776af324e 100644
--- a/src/vs/workbench/api/node/extHostTask.ts
+++ b/src/vs/workbench/api/node/extHostTask.ts
@@ -59,7 +59,7 @@ export class ExtHostTask extends ExtHostTaskBase {
 				throw new Error('Task from execution DTO is undefined');
 			}
 			const execution = await this.getTaskExecution(executionDTO, task);
-			this._proxy.$executeTask(executionDTO.task).catch(error => { throw new Error(error); });
+			this._proxy.$executeTask(executionDTO.task).catch(() => { /* The error here isn't actionable. */ });
 			return execution;
 		} else {
 			const dto = TaskDTO.from(task, extension);
@@ -75,7 +75,7 @@ export class ExtHostTask extends ExtHostTaskBase {
 			}
 			// Always get the task execution first to prevent timing issues when retrieving it later
 			const execution = await this.getTaskExecution(await this._proxy.$getTaskExecution(dto), task);
-			this._proxy.$executeTask(dto).catch(error => { throw new Error(error); });
+			this._proxy.$executeTask(dto).catch(() => { /* The error here isn't actionable. */ });
 			return execution;
 		}
 	}