fatal: unable to read after commit

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Hi folks,

I am a heavy user of git now at version 2.20.1 on debian.

Since some weeks I have the problem that I get often "fatal: unable to read ..." and a unclear repository after a git commit. The commit itself is correct and so a git reset --hard helps to fix the issue.

Any Idea what could be the reason for that problem. I encounter it on different repositories so not limited to one.

Any hint how to find out the reason?

Regards
   Klaus

Ps. I am not subscribet to the list, so please keep me in the response.
- -- 
Klaus Ethgen                                       http://www.ethgen.ch/
pub  4096R/4E20AF1C 2011-05-16            Klaus Ethgen <Klaus@Ethgen.ch>
Fingerprint: 85D4 CA42 952C 949B 1753  62B3 79D0 B06F 4E20 AF1C
-----BEGIN PGP SIGNATURE-----
Comment: Charset: ISO-8859-1

iQGzBAEBCgAdFiEEMWF28vh4/UMJJLQEpnwKsYAZ9qwFAlyvbvEACgkQpnwKsYAZ 9qyeggwAjLjfP8M2+Bybc6WFCnPjT2tAoU2Rpt1w7lPfycbqOykwa8YHML9Hy4OW G+ODpR3SXnRgKDzQ8xpz7i5/6pNC3ZlAYrvnOQFPHpL6zlOWr9aeDo8wai8FzVKk 4ei32u3Gw/bu0tH6D/SKxCVjC8sZzHWx+NjUDJh8ld3ln5RmF5XpK5+UvVak/nal rj+MxUyB1Aklho5cnwlFbdW0aUOM6Iom4G5uZz3dfh3p2VuPNzbbU/RKYXHGrJIB 01/Wh67r9XsML8z2kwYrpmT6Hcpuz/uuuIw81fHp55419YcbtS9bCJsYwYy0BGo0 LWJX5PzyMbWbbJE6oS1YDZOfnY/W/iIdq9JysMsyt1+nURcWNkHdOQ4+vY5DeBDa /kEDH9BLyzGddLAShYvspMpZg2J5c0v1FtX9N7q4A/vUyemevpQKJq+qJPV1WelI 7Hs45gvWj7oTOxVE4yJtMYkdO1jZLznVSLG36XT06+ciXiBl2FmVkTZ9yQaRse9L bIWDVDXp =4x1q -----END PGP SIGNATURE-----