uncaught syntaxerror unexpected token U JSON
That error is normally seen when the value given to JSON.parse is actually undefined.So, I would check the code that is trying to parse this - most likely you are not parsing the actual string shown here.
I was getting this message while validating (in MVC project).For me, adding ValidationMessageFor element fixed the issue.
To be precise, line number 43 in jquery.validate.unobtrusive.js caused the issue:
replace = $.parseJSON(container.attr("data-valmsg-replace")) !== false;
The parameter for the JSON.parse may be returning nothing (i.e. the value given for the JSON.parse is undefined)!
It happened to me while I was parsing the Compiled solidity code from an xyz.sol file.
import web3 from './web3';import xyz from './build/xyz.json';const i = new web3.eth.Contract( JSON.parse(xyz.interface), '0x99Fd6eFd4257645a34093E657f69150FEFf7CdF5');export default i;which was misspelled as
JSON.parse(xyz.intereface)which was returning nothing!