tensorboardが起動できない。(エラーが出る。以前はできた)

以前できたMNISTでの学習をtensorboardで見ようとするとエラーが出る

tensorboard --　logdir logs

でtensorboardを起動するとURLが出ずに

2020-08-27 04:19:23.766570: W tensorflow/stream_executor/platform/default/dso_loader.cc:59] Could not load dynamic library 'cudart64_101.dll'; dlerror: cudart64_101.dll not found
2020-08-27 04:19:23.776923: I tensorflow/stream_executor/cuda/cudart_stub.cc:29] Ignore above cudart dlerror if you do not have a GPU set up on your machine.
usage: tensorboard [-h] [--helpfull] [--logdir PATH] [--logdir_spec PATH_SPEC]
                   [--host ADDR] [--bind_all] [--port PORT]
                   [--purge_orphaned_data BOOL] [--db URI] [--db_import]
                   [--inspect] [--version_tb] [--tag TAG] [--event_file PATH]
                   [--path_prefix PATH] [--window_title TEXT]
                   [--max_reload_threads COUNT] [--reload_interval SECONDS]
                   [--reload_task TYPE] [--reload_multifile BOOL]
                   [--reload_multifile_inactive_secs SECONDS]
                   [--generic_data TYPE]
                   [--samples_per_plugin SAMPLES_PER_PLUGIN]
                   [--debugger_data_server_grpc_port PORT]
                   [--debugger_port PORT]
                   [--whatif-use-unsafe-custom-prediction YOUR_CUSTOM_PREDICT_FUNCTION.py]
                   {serve,dev} ...
tensorboard: error: invalid choice: 'logs' (choose from 'serve', 'dev')