Shards limit reached?

[Ancient Mariner]

I was farming through Battlefield as always to get troppers points and find evo runes, when suddenly after 15-20 stages farmed, the game randomly stopped me with a window message that says i overcame the inventory's limit of 1 shard (skill shard maybe? since i'm holding 2 of them to wait for new characters to improve? But in this case i'm holding them since 2 days...or does it mean any other shard? I don't get it).
I don't have many full stacks of shards so i have no clue what the problem may be

Have anyone else ever experienced this?

[hold]

Nothing to do with skill shards ... just means that your shard inventory is full ... use some or sell some but sell carefully (and don't sell 3* evo runes / shards too hasty)

[Ancient Mariner]

Oh ok i thought you could store much more than that! thank you