Adel

Did you read what I typed above? Get Brow. Remove the model. No more errors!

Try to find the model in data/rdata.grf and if it's not there like Aerie said take another model (something big) and name it with the name shown on the error (so the model will appear in-game). Go in-game and check where this erroring model is placed. Open the map with browedit and remove that model.