You may encounter this error message after a post to Facebook fails to be published:
Please reduce the amount of data you’re asking for, then retry your request
This is a known bug on Facebook's end for their API, (below is a list of this same issue reported to Facebook over the years by other development teams). They have stated that the cause is their servers run out of memory.
Sometimes the post is published successfully to your Facebook Page, even though Vista Social shows the post failed.
You should check your Facebook Page to see if the post was published or not, and take action accordingly.
If retrying the post continues to fail, the Facebook API may be unable to publish the post so you may want to try scheduling the post for a later time.
We continue to monitor the reported bugs to Facebook and await a resolution by their team.