I am reporting this error as the error pop-up says.

The mod Factorio Contracts (1.0.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event FactorioContracts::on_robot_built_entity (ID 18)
FactorioContracts/control/events.lua:344: bad argument #3 of 3 to 'index' (string expected, got nil)
stack traceback:
[C]: in function '__index'
__FactorioContracts/control/events.lua:344: in function <FactorioContracts/control/events.lua:340>

The error occurred when I placed the Contract Building for the first time.

have you given 1.0.4 a try since you are crashing on 1.0.3.

Did you built a contract terminal with robots?

Anyway, will fix that tomorrow...

Should be fixed in 1.0.5

Did you built a contract terminal with robots?

Anyway, will fix that tomorrow...

I had not built it with robots, I attempted to place it by hand. I will give 1.0.5 a try.