Looks like you nested a mod folder incorrectly and the path to a texture file is broken.
Make sure you have the folders nested properly. For example the path toOSK.BepInEx.Hp2BaseMod.dll
must beHuniePop 2 - Double Date\BepInEx\plugins\Hp2BaseMod\OSK.BepInEx.Hp2BaseMod.dll.
Do not have extra folders in between or the mod will not be loaded!