At one of our customers an error occurs during Excel export, no matter if group or report. These lines can be found in the log files.

ERROR generating excel file. HTTP status:200 Message: A certificate is required to complete client authentication
Feb 9 2023 12:29:44.339 8380 9112 1 ERROR generating excel file. Message - Error generating report. .A certificate is required to complete client authentication

The customer uses an SSL certificate. Until recently, everything ran smoothly. Also the certificate is valid and not expired.
According to the customer, nothing has been changed on the network.

Also the control center is displayed without any errors.

Do you have any ideas and/or solutions?

Many thanks in advance.