Thanks Dimitris33, I renamed my plugins but the problem persisted. I have also removed the last theme I installed before the occurrence but to no avail. I can visit all my sub-sites but the page goes blank when I try visiting my network dashboard.
I am experincingba similar problem with your plugin. I cannot access my admin-url after using your plugin to change my admin-url from /wp-admin to /bdcsite. My permalink was changed from default to custom before this. What do I do?