Had that on 19.78. Trying 19.77 - managed to get it working by clicking on the logo and hitting play and it managed to run.
Will see if I get more than 5 mins now (had to put in license again due to clean install of bot)
I have however seen an issue that once a card is trained to maximum (the Primal as my example) it does indeed get stuck by trying to fortify or improve it when it isn't possible.
Apologies but it took a bit of time to max the card to see this occur.