parameters in produce block
If newgrf parameters and/or formulas are used within produce block,
some openttd run-errors and warnings appears in console.
For example, in attached test grf, there are warnings like:
NewSpriteGroup: Unsupported feature nnn, skipping
GetGroupFromGroupID(0xNN:0xNN): Groupid 0x00xx does not exist, leaving empty
Other fatal error related to produce block can be
DecodeSpecialSprite: Tried to read past end of pseudo-sprite data
however not reproduced by attached simple example.