[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_7.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_6.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_5.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_4.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_3.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_2.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_1.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_rainbow_0.png, java.io.FileNotFoundException
[20:13:13] [Client thread/INFO]: Dense Ores: Succesfully generated dense ore texture for 'gold_ore' with background 'stone'. Place gold_ore_dense.png in the assets folder to override.
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_0.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_1.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_2.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_3.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_5.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_4.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_7.png, java.io.FileNotFoundException
[20:13:13] [Client thread/ERROR]: Using missing texture, unable to load carpentersblockscachedresources:textures/blocks/designs/bed/cache/carpenters_quilt_multicolor_6.png, java.io.FileNotFoundException

this (edit:) almost always happens since it's sometimes easy to miss, don't worry this is nothing to fret about

This must have slipped through the cracks.

If the cache has never been created it will usually throw this error when reloading resource packs for the first time. But after that it should be fine.

If you see bed textures correctly in game then it's a non-issue.