# Is it a bug with parameter collection? **URL:** \ **Category:** Rendering\ **Tags:** bug, unreal-engine, bug-report, question\ **Created:** [April 2, 2015, 10:46pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581 "2015-04-02T22:46:23Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![NKos](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@NKos](https://forums.unrealengine.com/u/NKos)\ **Post date:** [April 2, 2015, 10:46pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/1 "2015-04-02T22:46:23Z")
I have a simple parameter collection (screen\_01) and a simple material (screen\_02). But when I compile this material it uses only first one parameter from the list (screen\_03). Am I doing something wrong or this is a bug? I am using 4.7.4 ![37112-screen_01.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/5/5/c/55c64c89af1124c1f70be915b36c9c923b083fff.jpeg) ![37114-screen_02.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/d/9/6d904fe0e61be1f9f350f9c20ffd7bb9c87c19f1.jpeg) ![37115-screen_03.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/3/5/83569e01c67bf2260eb0c3f8638b5f07a387ed62.jpeg) ---
**Author:** ![NKos](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@NKos](https://forums.unrealengine.com/u/NKos)\ **Post date:** [April 3, 2015, 9:35am UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/2 "2015-04-03T09:35:05Z")
Well… While I’m investigated this bug, I rename parameters, delete them and add new ones to the list, etc… it just fixed them self. I don’t know how, but now it works! And i didn’t notice any regularity of this bug ---
**Author:** ![todernst](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@todernst](https://forums.unrealengine.com/u/todernst)\ **Post date:** [June 15, 2015, 5:32pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/3 "2015-06-15T17:32:48Z")
I’m having this problem too. I’m using 24 parameters and only the second one is reverting to the Parameter name no matter what I do. I’ve been trying to fix this for 3 days now and having had the same luck of it just automatically working again. NKos, do you remember the order of operations you took when it finally fixed itself? ---
**Author:** ![NKos](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@NKos](https://forums.unrealengine.com/u/NKos)\ **Post date:** [June 15, 2015, 5:54pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/4 "2015-06-15T17:54:02Z")
When you create your Parameter collection DON’T use duplicate ![46461-screen_04.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/5/1/8/5183ba68a1724eae593cc34e5f8c4c009492f287.jpeg) Just use Adds element ![46462-screen_05.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/6/9/669b60b4157b7104d10ebe0ef7621c4902386fad.jpeg) And i still think that there is a bug ---
**Author:** ![Lovecraft\_K](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Lovecraft\_K](https://forums.unrealengine.com/u/Lovecraft_K)\ **Post date:** [June 15, 2015, 6:34pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/5 "2015-06-15T18:34:39Z")
Hi NKos - I have reported the issue with Duplicated Parameters in the Collection Parameters as UE-17063. Your use of the add instead of the duplicate is the intended way to add new parameters to the MPC. Thank You Eric Ketchum ---
**Author:** ![todernst](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@todernst](https://forums.unrealengine.com/u/todernst)\ **Post date:** [June 17, 2015, 7:56pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/6 "2015-06-17T19:56:37Z")
I can add my confirmation that this worked for me. Thank you, NKos ---
**Author:** ![AntonioE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@AntonioE](https://forums.unrealengine.com/u/AntonioE)\ **Post date:** [April 20, 2016, 10:24pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/7 "2016-04-20T22:24:09Z")
omg… I was having this same problem! THANKS! ---
**Author:** ![anonymous\_user\_4071fa6e1](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_4071fa6e1](https://forums.unrealengine.com/u/anonymous_user_4071fa6e1)\ **Post date:** [June 14, 2016, 7:55am UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/8 "2016-06-14T07:55:29Z")
I also (just) had this bug (4.11.2). I duplicated a collection parameter element and renamed it like I have always done without issue. (It is quicker to duplicate and edit an element in a collection if the names are incremental, e.g. myVal\_1, myVal\_2, etc). Today, however, the value for an element I duplicated was not being read from my material as expected. I saw NKos’ post and decided to delete the erroneous element and recreate it using [+Add] instead of [Duplicate] which indeed fixes (well …works around) the bug. ---
**Author:** ![SVR33](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/svr33/32/906589_2.png) [@SVR33](https://forums.unrealengine.com/u/SVR33)\ **Post date:** [April 2, 2017, 12:44pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/9 "2017-04-02T12:44:40Z")
It seems this issue still exists in some fashion. I’m in 4.15.0 and couldn’t, for the life of me, figure out why my MPC wasn’t updating when being called by a BP. The really odd thing is that it had been working for 3 months and I hadn’t touched it. I found this thread, tried deleting the parameter element and recreating it, and it works again. ---
**Author:** ![Elseware-Experience](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Elseware-Experience](https://forums.unrealengine.com/u/Elseware-Experience)\ **Post date:** [July 25, 2019, 3:56pm UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/10 "2019-07-25T15:56:38Z")
Fixed it for me as well and I am using 4.22 … any news on fixing this definetly ? ---
**Author:** ![NKos](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@NKos](https://forums.unrealengine.com/u/NKos)\ **Post date:** [July 26, 2019, 8:27am UTC](https://forums.unrealengine.com/t/is-it-a-bug-with-parameter-collection/313581/11 "2019-07-26T08:27:12Z")
Well, just now try it in 4.20.3 and all works well, duplicate and add. So I believe it’s fixed.