Install Updates Issue

[lc6529]

First time I've seen this error - any suggestions?

After attempting an update today a message popped up that said to post the log into the forum

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Reading package lists...
Building dependency tree...
Reading state information...
Calculating upgrade...
The following packages were automatically installed and are no longer required:
  brasero-common cdrdao dvd+rw-tools growisofs gthumb-data libao-common libao4
  libbrasero-media3-1 libclutter-1.0-0 libclutter-1.0-common
  libclutter-gtk-1.0-0 libcogl-common libcogl-pango20 libcogl-path20 libcogl20
  libllvm10 libtotem-plparser-common libtotem-plparser18
  linux-headers-5.4.0-52 linux-headers-5.4.0-52-generic linux-headers-5.4.0-53
  linux-headers-5.4.0-53-generic linux-headers-5.4.0-54
  linux-headers-5.4.0-54-generic linux-headers-5.4.0-56
  linux-headers-5.4.0-56-generic linux-headers-5.4.0-58
  linux-headers-5.4.0-58-generic linux-image-5.4.0-52-generic
  linux-image-5.4.0-53-generic linux-image-5.4.0-54-generic
  linux-image-5.4.0-56-generic linux-image-5.4.0-58-generic
  linux-modules-5.4.0-52-generic linux-modules-5.4.0-53-generic
  linux-modules-5.4.0-54-generic linux-modules-5.4.0-56-generic
  linux-modules-5.4.0-58-generic linux-modules-extra-5.4.0-52-generic
  linux-modules-extra-5.4.0-53-generic linux-modules-extra-5.4.0-54-generic
  linux-modules-extra-5.4.0-56-generic linux-modules-extra-5.4.0-58-generic
Use 'apt autoremove' to remove them.
The following packages will be upgraded:
  libwavpack1
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 77.3 kB of archives.
After this operation, 0 B of additional disk space will be used.
Err:1 http://security.ubuntu.com/ubuntu focal-security/main amd64 libwavpack1 amd64 5.2.0-1ubuntu0.1
  404  Not Found [IP: 91.189.91.39 80]
E: Failed to fetch http://security.ubuntu.com/ubuntu/pool/m..._amd64.deb  404  Not Found [IP: 91.189.91.39 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?