Character elevates

Hi everybody!

I’m creating a game and I’m working on it since many months. So I’m not really new to UE4. Now my very strange problem:

After some time I was the first time ever not creating something as much as by myself as possible. I’ve added the “Physical Water Surface” from the store. No, it’s not a support case for the creater of this. Please read furthur. Anyway, I’ve changed nothing while using this water except the water surface and my character. All was going fine when suddenly after I didn’t test play for a while the charcacter begun to “elevate”. As soon as I play the character he does constantly elevate upwards to the sky. What the ****? After that I tried so much stuff to fix that, that I couldn’t possibly list all here. But I deleted at the end EVERYTHING in this level and added a standart static mesh cube from the editor and a light, placed the character on the mesh and still was elevating!?!? I’ve checked all the character movement, game mode, level blueprint, character blueprint and many many more I could think of and compared them to older versions from the 4.10 version. Everything was the same. I haven’t changed anything that could lead to this effect and didn’t find any such changes while comparing. The strangest fact is the following: I’ve two separate levels that’re containing very different maps. I haven’t touched the first one since I’d begun to build the second level that much later did contain the water. Still - when I now test play the first map (which I didn’t touch) I’m also elevating! And more fun facts: I’ve test played with a completely different free character from the store (the maximo pack) and even asinged the standard player controller from the UE4 engine - the one that comes with the standard ThirdPerson pack. And I was STILL elevating. A completely new level from the scratch, containing my level blueprint, with unedited standard player controller with an unedited (in the past time working normaly) maximo pack character still causes the problem. So this could mean that the level blueprint is the only possible problem causer. But I didn’t change anything in the blueprint since starting to create the second level (which shares the same level blueprint as the first level - to clone the first level, delete everything and delete all that’s not needed or doensn’t work in the level blueprint was the quickest way to have all I needed in the blueprint for the new level.).
I was a huge idiot and wasn’t createing many backups since I did switch to 4.12. That means A LOT is gone if I’m not able to fix this. I’m trying to fix that since many weeks. Soon I’m going crazy. Please somebody help me!!

Edit: I actually did change something other as listed above. I’m sometimes adding free packs from the store for learning purposes. I’ve added the Infinity Blades pack. It used to be for mobile only. Since I’m creating a PC game it was useless for me. But I discovered that I’m now able to add and use it with a PC project. May this cause the problem? Even if nothing of the pack is actually used in the level?

Thank you very much!!!