This is how to fix this error:
An HTTPS binding already exists for the specified IP address and port combination!
netsh http show sslcert
if too long
netsh http show sslcert > sslcert.txt
then delete the bindings:
netsh http delete sslcert ipport=0.0.0.0:443
netsh http delete sslcert ipport=[::]:443
See also Troubleshooting SSL-Binding in SSRS
Deleting URL reservation
netsh http show urlacl
netsh http delete urlacl URL=http://+:80
Delete the URLs you don't want, using the exact same values shown on the "Reserved URL" line from the "show" command:
netsh http delete urlacl URL=
netsh http delete urlacl URL=http://+:80/ReportServer/
netsh http delete urlacl URL=https://+:443/ReportServer/
netsh http delete urlacl URL=http://+:80/Reports/
netsh http delete urlacl URL=https://+:443/Reports/
And if you wrongly did
netsh http delete urlacl URL=http://+:8082/
then you can do
netsh http add urlacl url=http://+:8082/ user="NT SERVICE\SQLServerReportingServices"
An additional problem is the user SSRS runs under - it might not have the necessary rights for WMI management ...