Netsafe issues are a small mistake Blizzard made with an update to object data: not every SLK got updated to include the “netsafe” field, which is used for war3mapSkin.w3* file generation. The netsafe error is not harmful.
The PopcornFX rebaking error is a larger mistake Blizzard made, where not all pkb files in 1.33 are correctly loadable by the PopcornFX version that comes in the game. They have to fix these files for the errors to go away