The only reason there would be a Constants folder in it is if the path for the Strive mod folder was set to that folder instead of ".../Strive/mods". While Strive's mod system was updated to use mods along any path in the designated mod folder, the mods themselves often use only an exact relative file path. In this case it expects "<the mod folder>/randomportraits/", but that path is not valid with the current path assigned as the Strive mod folder(edit: it's looking for ".../Strive/mods/randomportraits/randomportraits/").