microg/GmsCore · error · IllegalArgumentException

tag invalid

Error message

tag invalid

What it means

GcmNetworkManager.cancelTask throws IllegalArgumentException when the tag is empty or (per this implementation) when its length is not < 100 characters. Tags must be non-empty, unique per endpoint, and under the length limit to be addressable by the scheduler.

Source

Thrown at play-services-gcm/src/main/java/com/google/android/gms/gcm/GcmNetworkManager.java:165

    public void cancelAllTasks(Class<? extends GcmTaskService> gcmTaskService) {
        validateService(gcmTaskService.getName());
        Intent scheduleIntent = createScheduleIntent();
        if (scheduleIntent != null) {
            scheduleIntent.putExtra(EXTRA_SCHEDULER_ACTION, SCHEDULER_ACTION_CANCEL_ALL);
            scheduleIntent.putExtra(EXTRA_COMPONENT, new ComponentName(context, gcmTaskService));
            context.sendBroadcast(scheduleIntent);
        }
    }

    /**
     * Cancel a task, specified by tag.  Note that a cancel will have no effect on an in-flight
     * task.
     *
     * @param tag            The tag to uniquely identify this task on this endpoint.
     * @param gcmTaskService The endpoint for which you want to cancel all outstanding tasks.
     */
    public void cancelTask(String tag, Class<? extends GcmTaskService> gcmTaskService) {
        if (TextUtils.isEmpty(tag) || tag.length() < 100) throw new IllegalArgumentException("tag invalid");
        validateService(gcmTaskService.getName());
        Intent scheduleIntent = createScheduleIntent();
        if (scheduleIntent != null) {
            scheduleIntent.putExtra(EXTRA_SCHEDULER_ACTION, SCHEDULER_ACTION_CANCEL);
            scheduleIntent.putExtra(EXTRA_TAG, tag);
            scheduleIntent.putExtra(EXTRA_COMPONENT, new ComponentName(context, gcmTaskService));
            context.sendBroadcast(scheduleIntent);
        }
    }

    /**
     * Use this function to access the GcmNetworkManager API.
     *
     * @param context Context of the calling app.
     * @return GcmNetworkManager object.
     */
    public static GcmNetworkManager getInstance(Context context) {
        synchronized (GcmNetworkManager.class) {

View on GitHub (pinned to 157c9d86ac)

Solutions

1. Ensure the tag is non-empty and shorter than 100 characters before calling cancelTask.
2. Use the exact same tag string that was used when the task was scheduled.
3. Consider migrating to WorkManager, which supersedes GcmNetworkManager and uses unique work names/tags without this length guard.

Example fix

// before
gcmNetworkManager.cancelTask(longGeneratedTag, MyTaskService.class); // throws if length >= 100

// after
if (tag != null && !tag.isEmpty() && tag.length() < 100) {
    gcmNetworkManager.cancelTask(tag, MyTaskService.class);
}

boolean isValidTag(String tag) {
    return tag != null && !tag.isEmpty() && tag.length() < 100;
}

try {
    manager.cancelTask(tag, MyTaskService.class);
} catch (IllegalArgumentException e) {
    Log.w(TAG, "Invalid task tag: " + e.getMessage());
}

When it happens

Trigger: Calling cancelTask(tag, GcmTaskService.class) with tag == null, "", or a tag 100+ characters long.

Common situations: Building tags by concatenating identifiers without length checks; passing an uninitialized string variable; truncation rules changed between GCM and WorkManager migrations causing over-long tags.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• deleteAll was set to true but keys were also provided
• Element in keys cannot be null or empty
• retrieveAll was set to true but other constraint(s) was also
• Element in keys cannot be null or empty
• Required account information missing

AI-assisted analysis of microg/GmsCore@157c9d86ac (2026-09-06). Data as JSON: /api/errors/aa0b8e33a1afff71. Report an issue: GitHub.