Slow pages loading, time-outs, no pics after 4.8.2 update GL-MT6000

I tried to install luci-app-upnp with the new beta firmware but i got this error:

Collected errors: * pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.246-1-d4a7d36962bb6218ebd94bf040ac560e) for kmod-nf-reject * pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.246-1-d4a7d36962bb6218ebd94bf040ac560e) for kmod-nf-ipt * pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.246-1-d4a7d36962bb6218ebd94bf040ac560e) for kmod-ipt-core * pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.246-1-d4a7d36962bb6218ebd94bf040ac560e) for kmod-nf-reject6 * pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.246-1-d4a7d36962bb6218ebd94bf040ac560e) for kmod-nf-ipt6 * pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.246-1-d4a7d36962bb6218ebd94bf040ac560e) for kmod-ip6tables