Cant upgrade lvl 10 item to tier 2

You can see on the bottom of the screen for this weapon only it says I need a lvl 10 sniper cannon. I press evolve and it gives an error and links me to the market where I cant even buy another if I wanted to. I have completed the process separately with a regular cannon with no problems. Restarted app and phone with no success

 

The image you posted is not working, appears to be a broken link or incorrect implementation.

To evolve an item you need a duplicate of it. That means when you go to upgrade your sniper cannon where it says 0/1 Sniper Cannons, it mean you need an ADDITIONAL one.
When you evolved your regular cannon you clearly had a cannon sitting in your inventory and didn't realise the second cannon was destroyed in order to evolve your first one.

 

Weird. But the market won't let me buy one so I have to wait to get box lucky? Lame

 

You can only buy an item if you don't already own one. So yeah you just have to get lucky with boxes.
I also agree that it is silly that it takes you to the shop even though it knows you can't buy one considering you must own one to be trying to evolve it...

 

There has got to be another answer to this problem. This is where I am, too. I have an uncommon Sniper. I have everything I need (I think) to evolve it. But the message says I am missing an uncommon Sniper when it is right there sitting in my inventory. Looks to be the same for all items, not just the Sniper. Only thing I can do is to go buy a rare Sniper? Maybe, but I cannot buy an epic Sniper.

 

Because you a need a duplicate which u can get only by luck....So just wait for one to pop up.

 

The duplicate has to be of the SAME rarity as the one you are trying to evolve.