There are two reasons for this problem
first, the GPU computing power and the python version do not match
Second, the server uses a combination of graphics cards with different computing power
on the first point, pytorch no longer supports graphics cards with computing power less than 3.7 after 1.3.0. You can reinstall the lower version of pytorch. The corresponding version can be found in the following link:
torch, torchvision historical version download
common graphics card computing power is as follows

GPU	Compute Capability
NVIDIA TITAN RTX	7.5
Geforce RTX 2080 Ti	7.5
Geforce RTX 2080	7.5
Geforce RTX 2070	7.5
Geforce RTX 2060	7.5
NVIDIA TITAN V	7.0
NVIDIA TITAN Xp	6.1
NVIDIA TITAN X	6.1
GeForce GTX 1080 Ti	6.1
GeForce GTX 1080	6.1
GeForce GTX 1070	6.1
GeForce GTX 1060	6.1
GeForce GTX 1050	6.1
GeForce GTX TITAN X	5.2
GeForce GTX TITAN Z	3.5
GeForce GTX TITAN Black	3.5
GeForce GTX TITAN	3.5
GeForce GTX 980 Ti	5.2
GeForce GTX 980	5.2
GeForce GTX 970	5.2
GeForce GTX 960	5.2
GeForce GTX 950	5.2
GeForce GTX 780 Ti	3.5
GeForce GTX 780	3.5
GeForce GTX 770	3.0
GeForce GTX 760	3.0
GeForce GTX 750 Ti	5.0
GeForce GTX 750	5.0
GeForce GTX 690	3.0
GeForce GTX 680	3.0
GeForce GTX 670	3.0
GeForce GTX 660 Ti	3.0
GeForce GTX 660	3.0
GeForce GTX 650 Ti BOOST	3.0
GeForce GTX 650 Ti	3.0
GeForce GTX 650	3.0
GeForce GTX 560 Ti	2.1
GeForce GTX 550 Ti	2.1
GeForce GTX 460	2.1
GeForce GTS 450	2.1
GeForce GTS 450*	2.1
GeForce GTX 590	2.0
GeForce GTX 580	2.0
GeForce GTX 570	2.0
GeForce GTX 480	2.0
GeForce GTX 470	2.0
GeForce GTX 465	2.0
GeForce GT 740	3.0
GeForce GT 730	3.5
GeForce GT 730 DDR3,128bit	2.1
GeForce GT 720	3.5
GeForce GT 705*	3.5
GeForce GT 640 (GDDR5)	3.5
GeForce GT 640 (GDDR3)	2.1
GeForce GT 630	2.1
GeForce GT 620	2.1
GeForce GT 610	2.1
GeForce GT 520	2.1
GeForce GT 440	2.1
GeForce GT 440*	2.1
GeForce GT 430	2.1
GeForce GT 430*	2.1
GPU	Compute Capability
Tesla K80	3.7
Tesla K40	3.5
Tesla K20	3.5
Tesla C2075	2.0
Tesla C2050/C2070	2.0

On the second point, if you make an error in the mmcv framework, recompile mmcv according to the computing power of your graphics card. Take two graphics cards with computing power of 6.1 and 7.5 as examples to compile. The commands are as follows:

TORCH_CUDA_ARCH_LIST="6.1;7.5"   pip install mmcv-full == {mmcv_version} -f   	https://download.openmmlab.com/mmcv/dist/{cuda version}/{pytorch version}/index.html

Among them, CUDA version and pytorch version are replaced by your version, such as cud101, torch 1.7.0
for specific corresponding information, please refer to GitHub of mmcv