ssl config error

hey guys im getting an error message when trying to use ssl on my server:

[emerg] 3108#6408: SSL_CTX_use_PrivateKey_file("C:\Users\Server\Desktop\host\myterms.co.uk\nginx/conf/ssl/myterms_co_uk.key") failed (SSL: error:0B080074:x509 certificate routines:X509_check_private_key:key values mismatch)


here is how i inclided my certificates

ssl_certificate ssl/domain.ca-bundle;
ssl_certificate_key ssl/domain.key;

domain.key is my private key
domain.ca-bundle is my cert bundle sent to me from where i bought my ssl

please let me know if you need anymore information...some help on this would be appreciated

thank you