Can not access network admin – multisite

Hi,

I have a website running as a multisite that I can no longer access the network admin.

network admin does not show up under the “My sites” menu
I also do not seem to have the plugins or updates tab like I previously did.

If I go to wp-admin/network/ I get the following error:
“Sorry, you are not allowed to access this page.”

I have checked file permissions & all folders are 755 & files are 644

I have always been able to access network admin in the past with no issues.

Any ideas on how to fix this?

Thanks in advance.