Error trying to setattribute lua bytecode

[spidercraft]

i was trying to do a setattribute of raw compiled bytecode stored in a output.bin file.
I could do that setattribute in roblox directly, but was impossible using lune

error converting Lua string to &str (invalid utf-8 sequence of 1 bytes from index 140)
[Stack Begin]
    Script '[C]'
    Script 'newcac', Line 11
[Stack End]

error converting Lua string to &str (invalid utf-8 sequence of 1 bytes from index 140)
[Stack Begin]
    Script '[C]'
    Script 'newcac', Line 11
[Stack End]