The size should not be a problem. I tested decoding and reencoding of the game files which are much bigger.
This looks like some broken utf8 <-> utf16 conversion. Try to decode your encoded file again and check if the results differ from your input csv.
If they do or if the file cannot be decoded again then please attach/sent me a minimal version of your csv file that is not working and I look into it.
Thank you for the reply.
The file cannot be decoded back.
Here is a log:
INFO - ENCODING ru.for_sbf.csv to ru.for_sbf.csv.w3strings (testscript: ru.for_sbf.csv.w3strings.ws)INFO - opening ru.for_sbf.csv...
INFO - identified language: ru
WARN - skipping id space check!
INFO - creating ru.for_sbf.csv.w3strings...
INFO - storing language: ru
INFO - storing 8 strings
INFO - creating ru.for_sbf.csv.w3strings.ws...
E:\Witcher3Moding\w3strings encoder-1055-0-2-1>call w3strings.exe --decode ru.for_sbf.csv.w3strings
w3strings decoder/encoder v0.2.1
INFO - DECODING ru.for_sbf.csv.w3strings to ru.for_sbf.csv.w3strings.csv
INFO - opening ru.for_sbf.csv.w3strings...
INFO - identified language: ru
INFO - found 8 strings
INFO - found 6 string key mapping infos
thread '<main>' panicked at 'error: found unknown data block [0x243e 1 bytes] after utf16 data!', src\w3strings\binary\redcoded.rs:213
INFO - identified language: ru
WARN - skipping id space check!
INFO - creating ru.for_sbf.csv.w3strings...
INFO - storing language: ru
INFO - storing 8 strings
INFO - creating ru.for_sbf.csv.w3strings.ws...
E:\Witcher3Moding\w3strings encoder-1055-0-2-1>call w3strings.exe --decode ru.for_sbf.csv.w3strings
w3strings decoder/encoder v0.2.1
INFO - DECODING ru.for_sbf.csv.w3strings to ru.for_sbf.csv.w3strings.csv
INFO - opening ru.for_sbf.csv.w3strings...
INFO - identified language: ru
INFO - found 8 strings
INFO - found 6 string key mapping infos
thread '<main>' panicked at 'error: found unknown data block [0x243e 1 bytes] after utf16 data!', src\w3strings\binary\redcoded.rs:213
Here is the link for not working csv: https://drive.google.com/file/d/0B4iZ-Xpp7wSHeVBqekZ1S0lwSDg/view?usp=sharing
If you delete just one character from anywhere in this file it will work and decode, but now it's not working.