getting a black page on multisite network

hello friends,
i have serious problem with mapping domain to my one of subcategories.

here is what i have done upto now.

01. installed WP on a addon domain (main-domain.com/addon-domain-folder)[WP is inside addon-domain-folder]
02. enabled multisite -> ok
03. created netwrok site
04. site are working ok
ex:
addon domain-> https://www.addon-domain-folder .com
virtual site -> https://www.addon-domain-folder .com/site2

05. installed domain mapping plug in.
06. added domain ok added IP (hosting -godaddy)
07. parked domain at godaddy
08. changed a rocords
09. im getting BLACK PAGE on [site2]

where did i go wrong?
please help