Try re-uploading the plugin’s folder to wp-content/plugins using FTP. If that doesn’t work, identify exactly which plugin you are using and then post in that plugin’s dedicated forum via its page in the Plugin Repository.
While learning a little about IP blocking and such over the past several days, I have occasionally seen spiders or whatever trying to directly access something within the wysija plugin folder. After you get things straightened out there, something like this might help protect against that:
###
# .htaccess file to harden certain WordPress folders (as recommended by Sucuri and others)
# ref: http://www.wpbeginner.com/wp-tutorials/how-to-disable-php-execution-in-certain-wordpress-directories/
# note: Do not use in ~/wp-content if your site uses TimThumb or similar scripts.
# 1. Place in ~/wp-content/uploads and check for problems...
#>> Blocks Plugins Garbage Collector plugin from scanning ~/wp-content/plugins/
# 2. else Place in ~/wp-content/ and check for problems...
# 3. Place in ~/wp-includes and check for problems...
## note: ~/wp-includes has many .php files.
###
<Files *.php>
deny from all
</Files>
sorry to hear that.
post your problem at link below. Plug in support should be able to help you with that.
http://wordpress.org/support/plugin/wysija-newsletters
