There are two possible reasons for this “Reconnecting…” in ComfyUI,

1. Network reconnection
2. ComfyUI crashed and restarting

Solution,

1. You need to check the log of ComfyUI, follow the step here https://comfyui-guides.runcomfy.com/ultimate-comfyui-how-tos-a-runcomfy-guide/how-to-view-logs-of-comfyui.
2. If the log says it is restarting and the queue size is 0 once “reconnecting…” disappears, then the ComfyUI crashed due to some reasons, either OOM (Out of memory) or some execution bugs.
3. There are two types of memory in the machine,
   1. RAM, for general calculation, consider it as the microwave, you can heat anything with it.
   2. VRAM, for image/video/multimedia processing, consider it as the toaster, the 4-slices one, you can only toast bread with it but it can toast the bread really fast.
   3. Pay special attention to both memories since either one of them could be “OOM”.
4. If you are working with long video generation, please follow the guide here https://comfyui-guides.runcomfy.com/ultimate-comfyui-how-tos-a-runcomfy-guide/limitation-of-rendering-long-videos.