Crosspost does not tweet

I am successfully using the plugin (ver 0.8.8) as a back end to my Tumblr blog. However, I have noticed that, even though I check the Send Tweet box and enter my text, no tweet occurs from Tumblr when the post is published. Also, any tweet text I previously entered does not show up in the WordPress post text box when I go back to edit it.

The debug info shows: [“tweet”]=> string(3) “off”

I don’t know if this is related, but I also occasionally see an error message in the Tumblr CrossPostr block immediately under the Destination & Content drop down. It reads:

Warning: Invalid argument supplied for foreach() in E:\web\thetraumapr\htdocs\wp-content\plugins\tumblr-crosspostr\tumblr-crosspostr.php on line 1775

When this occurs, the list of blogs is not enumerated in the drop down. It is empty.

Thanks for your assistance!

https://wordpress.org/plugins/tumblr-crosspostr/