Index.html file was not found error in ios using xcode?

Hi,
I have one v3 ios application when add platform that time was successfully added platform.then i opened application in xcode and run simulator or our iPhone will show index.html file was not found repeatedly but that file available inside of folder.what can i do?how do remove that error.
give me a solution.
os: mac
software: xcode
platform: ionic v3.