I can not view any …/wp-admin/… pages after installing "Microblog Poster" plugin

The problem after installing https://wordpress.org/plugins/microblog-poster/ :

I can login to …/wp-admin/… However when I select the menu links for ‘Network Admin > Dashboard’ the page hangs and takes a very long time to load. When it does myurl.com/network/ shows in the address bar but the WP Dashboard does not show, just what seems to be a blank front-end user page with no content (just a front-end user website menu). Note: A ‘Page not found’ 404 error page displayed last night, not this happens after leaving it to load for 4 minutes.

Attempted fix:

I tried accessing the Plugins page. This page also does not load in a similar fashion as explained above.

I tired giving you Support Access, but again the page does not load as explained above

I used FTP to delete the plugin folder from wp-content/plugins . This did not fix the problem

Special notes:

During installation the following anomalies happened:

1) Though installation seemed successful, on selecting ‘Network Activate’ the page hanged/froze

2) From that point onward I could not load my administrator pages

What I would NOT like:

I would greatly appreciate it if you do NOT do any of the following:

1) Google the problem and send me snippets of the first few links. I already spent all night last night trying online forums etc

2) Suggest what ‘may be the problem’ and ask me to ‘try this’

3) Ask me a surface-level question but not provide solutions

What I would like:

1) A step by step explanation of what the problem is likely to be; and what most likely could cause this type of behaviour by wordpress

2) Proposed steps for fixing the problem

3) I’d like you to login and have a closer look at what is going on. Please give instructions to privately send login details

Thanks in advance