KSampler error

Hello. I'm using ComfyUI on windows 11 PC. when i try to to do anything i get this error.
was working fine the other day i updated comfyui and my nvidia drivers.
any help would be appreciated.

Error occurred when executing KSampler:

No operator found for `memory_efficient_attention_forward` with inputs:
query : shape=(16, 4096, 1, 40) (torch.float16)
key : shape=(16, 4096, 1, 40) (torch.float16)
value : shape=(16, 4096, 1, 40) (torch.float16)
attn_bias :
p : 0.0
`decoderF` is not supported because:
xFormers wasn't build with CUDA support
attn_bias type is
operator wasn't built - see `python -m xformers.info` for more info
`flshattF@0.0.0` is not supported because:
xFormers wasn't build with CUDA support
operator wasn't built - see `python -m xformers.info` for more info
`tritonflashattF` is not supported because:
xFormers wasn't build with CUDA support
operator wasn't built - see `python -m xformers.info` for more info
triton is not available
`cutlassF` is not supported because:
xFormers wasn't build with CUDA support
operator wasn't built - see `python -m xformers.info` for more info
`smallkF` is not supported because:
max(query.shape[-1] != value.shape[-1]) > 32
xFormers wasn't build with CUDA support
dtype=torch.float16 (supported: {torch.float32})
operator wasn't built - see `python -m xformers.info` for more info
unsupported embed per head: 40