Error Enoent no such file or directory open

Hi I have an Ionic project and I have bootstrap.min.css inside my page as:
link rel="…" src=“assets/css/bootstrap.min.css”

When I build the application for android platform in --prod --release mode it gives me an error as:
Error: ENOENT: no such file or directory, open ‘apppath\src\pages\working-hours\assets\css\bootstrap.min.css’

NOTE:apppath is the path of project.I have not desired to tell that part.
The problem is my asset folder is under src but it shows me under my spesific folder!!!
How can I resolve this issue ?

Thanks.

I don’t understand the motivation for having two UI frameworks in a single app.

Dear @Lildiz

me also have same problem for command

ionic cordova run android --prod

with error

Error: ENOENT: no such file or directory, open '/home/user/mgov-master/src/pages/PropertyTaxsettings/assets/html/css/bootstrap.min.css'

Did You got solution ? please help

Thanks
Anes