Dear @thanapong,
Regarding your geometry, is there a structure separating the “honeycomb cells”? If not, the only repetitive elements would be the fuel rods and this should be pretty fast to implement, specially if you use the geometry editor to do so (maybe you are doing it already). Take a look to the following tutorial on how to use it in case you are not very familiar with it:
http://flair.cern/tutorial_geoedit.html
Note that even if you don’t have a technical drawing to insert as an image layer, you can still use the geometry editor capabilities to insert bodies, copy them, move them etc. as well as to define regions in order to create and place your geometry elements faster.
About your error: you are missing at least two very important cards (that were present in your previous input file), RANDOMIZ and START.
Once you have solved this, if you try to run your input, you will face another error message. The following post should help you to solve the problem:
Hope it helps,
Francisco