Could not add item to ManaMarket

[DragonStar]

I wanted to add 5 Black Dye to sell through ManaMarket for 120k each, but after sending !add 5 120000 Black Dye to ManaMarket, and opening the trade window, I couldn't add the Black Dye to trade from my inventory, either with drag and drop, or with the "Add" button on the trade window.

[Cassy]

That's because Manamarket has all slots in use.
There is no free slot available at the moment.

Here a discussion thread about it:
viewtopic.php?f=2&t=18718

[DragonStar]

Unfortunately, that doesn't appear to be the problem.

I tried adding a Topaz for 8,000 with !add 1 8000 Topaz and I was able to add the Topaz to the trade screen to give to ManaMarket, accept the trade, and see it for sale. Then I did !getback with the ID to get the Topaz back, and right after tried !add 5 120000 Black Dye again, and I still couldn't add the 5 Black Dye to the trade screen. I checked what was for sale on ManaMarket after closing the trade window, and nobody added another item for sale, so apparently the slot was still available while doing this.

This was tested with ManaPlus 1.5.1.17 on Windows 7 SP1.