The c89 command has an internal buffer, which is suitable for any option, option-argument, or operand that is valid for the c89 command. This buffer has a length limitation; the argument (option, option-argument, or operand) was too long. The portion of the argument that c89 could process is indicated in the message.
In the message text:
string is the maximum length.
Reenter the c89 command and make sure that the argument is not longer than the length indicated in the message.