I had the same problem now when updating again. The solution was to enter the docker container:
docker exec -it ff747e7168b7 /bin/sh
then when building it printed some errors:
/opt/nodebb # ./nodebb build
started
2021-11-11T11:56:22.384Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer.js (Ignoring)
2021-11-11T11:56:22.387Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/autocomplete.js (Ignoring)
2021-11-11T11:56:22.389Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/categoryList.js (Ignoring)
2021-11-11T11:56:22.389Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/controls.js (Ignoring)
2021-11-11T11:56:22.390Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/drafts.js (Ignoring)
2021-11-11T11:56:22.390Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/formatting.js (Ignoring)
2021-11-11T11:56:22.391Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/preview.js (Ignoring)
2021-11-11T11:56:22.391Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/resize.js (Ignoring)
2021-11-11T11:56:22.392Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/scheduler.js (Ignoring)
2021-11-11T11:56:22.392Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/tags.js (Ignoring)
2021-11-11T11:56:22.392Z [4567/320] - warn: [plugins] File not found: /opt/nodebb/node_modules/nodebb-plugin-composer-default/static/lib/composer/uploads.js (Ignoring)
2021-11-11T11:56:22.394Z [4567/320] - info: [build] Building in parallel mode
2021-11-11T11:56:22.395Z [4567/320] - info: [build] plugin static dirs build started
2021-11-11T11:56:22.398Z [4567/320] - info: [build] requirejs modules build started
2021-11-11T11:56:22.399Z [4567/320] - info: [build] client js bundle build started
2021-11-11T11:56:22.435Z [4567/320] - info: [build] admin js bundle build started
2021-11-11T11:56:22.435Z [4567/320] - info: [build] client side styles build started
2021-11-11T11:56:22.436Z [4567/320] - info: [build] admin control panel styles build started
2021-11-11T11:56:22.437Z [4567/320] - info: [build] templates build started
2021-11-11T11:56:22.437Z [4567/320] - info: [build] languages build started
2021-11-11T11:56:22.889Z [4567/320] - warn: [meta/css] File not found! nodebb-plugin-composer-default/static/less/composer.less
2021-11-11T11:56:22.994Z [4567/320] - warn: [meta/css] File not found! nodebb-plugin-composer-default/static/less/composer.less
2021-11-11T11:56:25.310Z [4567/320] - info: [build] plugin static dirs build completed in 2.915sec
2021-11-11T11:56:38.072Z [4567/320] - info: [build] client js bundle build completed in 15.673sec
2021-11-11T11:56:38.073Z [4567/320] - info: [build] admin js bundle build completed in 15.638sec
2021-11-11T11:56:38.081Z [4567/320] - info: [build] client side styles build completed in 15.646sec
2021-11-11T11:56:42.625Z [4567/320] - info: [build] admin control panel styles build completed in 20.189sec
2021-11-11T11:56:42.787Z [4567/320] - info: [build] languages build completed in 20.35sec
2021-11-11T11:56:43.191Z [4567/320] - info: [build] templates build completed in 20.754sec
2021-11-11T11:56:47.327Z [4567/320] - info: [build] requirejs modules build completed in 24.929sec
2021-11-11T11:56:47.329Z [4567/320] - info: [build] Asset compilation successful. Completed in 24.933sec.
Then I removed all plugins, enabled only quill, rebuild (no more missing file warnings) and restarted the docker container.
