To add some more details:

W1123 14:02:02.860316  1260 tls.cpp:101] Cannot read TLS server certificate(s): 'C:\Program files\osquery\certs\<cert_pem>'
W1123 14:02:02.875946  1260 tls_enroll.cpp:77] Failed enrollment request to https://<tls_host_fqdn>/osquery/enroll (Request error: certificate verify failed) retrying...

I installed osquery as a service

choco install osquery --params=/InstallService

.

Maybe you ended up with a literal

'

character in the certificate path?