# Cannot match collection types

**URL:** <https://help.galaxyproject.org/t/cannot-match-collection-types/16462>\
**Category:** Uncategorized\
**Tags:** collections, cutadapt, tool-help, rna\_star\
**Created:** [November 1, 2025, 8:02pm UTC](https://help.galaxyproject.org/t/cannot-match-collection-types/16462 "2025-11-01T20:02:13Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Valeriia\_Vasylieva](https://sea2.discourse-cdn.com/flex020/user_avatar/help.galaxyproject.org/valeriia_vasylieva/32/7917_2.png) [@Valeriia\_Vasylieva](https://help.galaxyproject.org/u/Valeriia_Vasylieva)\
**Post date:** [November 1, 2025, 8:02pm UTC](https://help.galaxyproject.org/t/cannot-match-collection-types/16462/1 "2025-11-01T20:02:13Z")

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I start a workflow and get this mistake right away.

> Invocation scheduling failed because an unexpected failure occurred at step 6: ‘Cannot match collection types.’

Step 6 is STAR and is connected to step 3 - cutadapt. The input to cutadapt is paired collection and the input to STAR is specified as Paired-end (collection). I do not see why it does not match.

 ![image](https://us1.discourse-cdn.com/flex020/uploads/galaxy/original/2X/3/3c0ff4d45cd6be9aacbb35512dce22cc70a0a951.png)

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**Author:** ![wm75](https://sea2.discourse-cdn.com/flex020/user_avatar/help.galaxyproject.org/wm75/32/56_2.png) [@wm75](https://help.galaxyproject.org/u/wm75)\
**Post date:** [November 2, 2025, 7:36am UTC](https://help.galaxyproject.org/t/cannot-match-collection-types/16462/2 "2025-11-02T07:36:59Z")

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Hi @Valeriia_Vasylieva,

my guess is that the complaint i about mismatch between the paired-end collection and the Gene model input to Star. Looks like you made this input a collection, too, which might not be what you want?

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<div class="post-metadata">

**Author:** ![Valeriia\_Vasylieva](https://sea2.discourse-cdn.com/flex020/user_avatar/help.galaxyproject.org/valeriia_vasylieva/32/7917_2.png) [@Valeriia\_Vasylieva](https://help.galaxyproject.org/u/Valeriia_Vasylieva)\
**Post date:** [November 2, 2025, 1:54pm UTC](https://help.galaxyproject.org/t/cannot-match-collection-types/16462/3 "2025-11-02T13:54:07Z")

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That was exactly the case! Thank you very much!