**Describe the bug** Crash of GUI while sending certain messages through HTTP API **To Reproduce** Send a complex message string (in my case, a long JSON-serialized object) through HTTP API. See extract of activity log: [2026-04-30T14:51:15.096][open-ephys][debug] Message string: {"event_type": "run_start", "event_timestamp": 1777553474.8286886, "run_type": "activity_mapper_run_and_stop", "run_output_folder": "C:\\Users\\fciotti\\Documents\\git_repos\\acute-cuff-experiment\\output\\activity_mapper\\2026-04-30_14-51-12_activity_mapper"} [2026-04-30T14:51:15.125][open-ephys][debug] Message Center sending message: {"event_type": "run_start", "event_timestamp": 1777553474.8286886, "run_type": "activity_mapper_run_and_stop", "run_output_folder": "C:\\Users\\fciotti\\Documents\\git_repos\\acute-cuff-experiment\\output\\activity_mapper\\2026-04-30_14-51-12_activity_mapper"} [2026-04-30T14:51:15.357][open-ephys][debug] Received PUT request [2026-04-30T14:51:15.357][open-ephys][debug] Trying to decode [2026-04-30T14:51:15.357][open-ephys][debug] Parsed [2026-04-30T14:51:15.357][open-ephys][debug] Message string: {"event_type": "stim_update", "event_timestamp": 1777553475.351187, "step": 0, "before_update_timestamp": 1777553474.8362625, "after_update_timestamp": 1777553474.8432636, "after_start_stim_timestamp": 1777553475.351187, "activity": {"loop_mode": null, "ramping_mode": null, "waveform_name": [], "cathodes": [], "anodes": [], "waveform_active": [], "amplitude": [], "frequency": [], "pulses": [], "offset": [], "duration": [120, 120, 120, 480], "ramping_duration": [], "ramping_start_percentage": [], "is_single_column": false, "is_single_waveform": false}} [2026-04-30T14:51:15.475][open-ephys][debug] 0: juce::SystemStats::getStackBacktrace + 0x93 1: Visualizer::endAnimation + 0x312b 2: juce::Time::getYear + 0x6a 3: UnhandledExceptionFilter + 0x1f3 4: strncpy + 0x2683 5: _C_specific_handler + 0x93 6: _chkstk + 0x9f 7: RtlLocateExtendedFeature + 0x597 8: KiUserExceptionDispatcher + 0x2e 9: juce::DirectoryContentsList::getFilter + 0x0 10: GenericProcessor::addEvent + 0x29 11: GenericProcessorBase::getName + 0x36f9 12: GenericProcessor::processBlock + 0x4b 13: juce::AudioProcessor::processBlockBypassed + 0x3fa 14: juce::AudioProcessorGraph::prepareToPlay + 0x6bd 15: juce::GenericAudioProcessorEditor::paint + 0x8fe 16: juce::AudioFormatWriter::writeFromFloatArrays + 0x9de0 17: juce::AudioProcessorPlayer::audioDeviceIOCallbackWithContext + 0x795 18: juce::AudioDeviceManager::audioDeviceIOCallbackInt + 0x206 19: juce::MidiOutput::run + 0x789 20: juce::Thread::threadEntryPoint + 0x70 21: juce::Thread::threadEntryPoint + 0x18c 22: wcsrchr + 0x150 23: BaseThreadInitThunk + 0x17 24: RtlUserThreadStart + 0x2c **Versions:** [2026-04-30T14:50:45.309][open-ephys] Open Ephys GUI v1.0.2 (Plugin API v10) [2026-04-30T14:50:45.309][open-ephys] JUCE v8.0.7 [2026-04-30T14:50:45.309][open-ephys] Operating System: Windows 11 [2026-04-30T14:50:45.309][open-ephys] CPU: Intel(R) Core(TM) Ultra 5 225U (14 core)