"the thing is that I don't know exactly where and how I can fix i"
nobody expected that but... you could have point to correct post or attachment or post your own. besides you still did not provide key info on your system. may want to check pinned topic READ FIRST.
don't have my resources at hand for such old system so not sure if 1034 refers to fieldbus or drive bus.
did you check in IOSYS.INI if interbus driver is enabled? try to comment it out. you can check forum for more info on IOSYS.INI
276 tells machine data is wrong for current robot. either robot is not connected (check cable X21-X31) or RDC is toast or it is not powered (check fuses) or machine data is really not the correct type. so compare what is on the robot label with what controller thinks connected robot is. post 33 explains this in details.
PID file is only present on the positionally accurate robots. if the robot was positionally accurate from the factory, feel free to contact KUKA with robot serial number and whatever else they are going to ask and they should send you copy of your robot PID file. other option is to extract it from this robot backup/archive. or if you do not really care about robot being positionally accurate, just turn off absolute accuracy and use it like a standard robot. if some day you come across correct PID file, you can always add it and get back to positional accuracy.
all of this is well documented and explained in depth on the forum. if none of this rings a bell, you may want to get someone local who knows KUKA robot to help you.