[Install] Invalid PEM encoded certificate

Your software
My Mautic version is: 5.0.3
My PHP version is: 8.0.1
My Database type and version is: Mysql

Your problem
My problem is:

Good morning,

I installed Mautic locally on my machine (WAMP/Windows).
I had the installation web interface and I filled in all the information.
But when I open mautic http://localhost/, I get the error page:
“Uh oh! I think I broke it. If I do it again, please report me to the system administrator!
500 Internal Server Error”

These errors are showing in the log:
[2024-02-16T09:09:03.257081+00:00] mautic.WARNING: PHP Warning - file_get_contents(D:\newsletter/var/cache/saml_default.key): Failed to open stream: No such file or directory - in file D:\newsletter\app\bundles\UserBundle\Security\SAML\Store\CredentialsStore.php - at line 84 {“hostname”:“PC-2”,“pid”:16968}
[2024-02-16T09:09:03.295986+00:00] mautic.CRITICAL: Uncaught PHP Exception InvalidArgumentException: “Invalid PEM encoded certificate” at D:\newsletter\vendor\litesaml\lightsaml\src\Credential\X509Certificate.php line 73 {“exception”:“[object] (InvalidArgumentException(code: 0): Invalid PEM encoded certificate at D:\newsletter\vendor\litesaml\lightsaml\src\Credential\X509Certificate.php:73)”} {“hostname”:“PC-2”,“pid”:16968}

Steps I have tried to fix the problem:
reinstaall but without success

Did you ever find the solution to this? Hitting the same issue. Thanks!