miniupnpd-nftables: multiple issues in 22.03.0 r19685-512e76967f

Maintainer: @stintel @ldir-EDB0 @neheb
Environment: 22.03.0 r19685-512e76967f , TP-Link TL-WDR3600 v1.

opkg install miniupnpd-nftables
Installing miniupnpd-nftables (2022-08-31-68c8ec50-1) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/packages/miniupnpd-nftables_2022-08-31-68c8ec50-1_mips_24kc.ipk
Installing libcap-ng (0.8.2-1) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/packages/libcap-ng_0.8.2-1_mips_24kc.ipk
Installing librt (1.2.3-4) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/targets/ath79/generic/packages/librt_1.2.3-4_mips_24kc.ipk
Installing libuuid1 (2.37.3-3) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/base/libuuid1_2.37.3-3_mips_24kc.ipk
Configuring libcap-ng.
Configuring librt.
Configuring libuuid1.
Configuring miniupnpd-nftables.
uci: Invalid argument
uci: Invalid argument

Section @redirect[0] (FTP) is disabled, ignoring section
Section @redirect[1] (HTTP) is disabled, ignoring section
Section @redirect[2] (HTTPS) is disabled, ignoring section
Section @redirect[6] (iperf) is disabled, ignoring section
Section @redirect[7] (RDP 1) is disabled, ignoring section
Section @redirect[8] (RDP 2) is disabled, ignoring section
Section @include[0] is not marked as compatible with fw4, ignoring section
Section @include[0] requires 'option fw4_compatible 1' to be considered compatible
Automatically including '/usr/share/nftables.d/table-post/20-miniupnpd.nft'
Automatically including '/usr/share/nftables.d/chain-post/dstnat/20-miniupnpd.nft'
Automatically including '/usr/share/nftables.d/chain-post/forward/20-miniupnpd.nft'
Automatically including '/usr/share/nftables.d/chain-post/srcnat/20-miniupnpd.nft'

Followed by a two minutes pause, then

Include '/usr/share/miniupnpd/firewall.include' failed with exit code -9
Collected errors:
 * resolve_conffiles: Existing conffile /etc/config/upnpd is different from the conffile in the new package. The new conffile will be placed at /etc/config/upnpd-opkg.

I've got questions:

• What does work now? What doesn't work now? How to check it?
• What are these errors? How to deal with them?

Lastly

opkg install luci-app-upnp
Installing luci-app-upnp (git-22.250.64651-a61c041) to root...
Downloading https://downloads.openwrt.org/releases/22.03.0/packages/mips_24kc/luci/luci-app-upnp_git-22.250.64651-a61c041_all.ipk
Configuring luci-app-upnp.
uci: Invalid argument
uci: Invalid argument

Again uci errors. What should I do?

Reproduce the package installation on the reported OpenWrt 22.03.0 TP-Link TL-WDR3600 setup, starting with the miniupnpd-nftables and luci-app-upnp configuration output. Read /etc/config/upnpd and /usr/share/miniupnpd/firewall.include, then trace the reported UCI errors and exit code -9. Done means identifying the causes and documenting or fixing the affected installation behavior.