I've never seen such a message before. It says that you don't have enough mana, so it looks like it is related to an issue with the resource credits calculation within the connected Steem node.
Please try to connect to a different node in settings and let me know if it works afterwards ;)
Thanks. I did as you said, trying 3 other settings, but with exactly the same results.
Do you think it may correct itself over a couple of days?
PS: To make certain the recipient account is a valid one, I posted a comment from it and it worked.
I hope so...
I think there is something wrong with the calculated available amount. As far as I know, it is impossible to reach a value smaller than 0. Would be interesting to see, if the number changes over time. Let's wait a day and see what happens.
If it shouldn't resolve itself, we should post the issue on GitHub, so that the blockchain devs can take a look at it.
Okay, thanks..had not noticed the amount was a negative.