Selling at customs (Workers & Resources: Soviet Republic)

Today can't sell to the Soviet customs alcohol food gravel - what is it?
If it's a bug, roofing felts I do not understand something produce from it grain - alcohol - from the warehouse to the indoor truck want to carry on Soviet customs-but on the truck illuminates the question mark checked the tape-loading in the warehouse unloading - customs - everything seems in order but the truck is worth