# JavaFX Application Thread

**URL:** https://discourse.jabref.org/t/javafx-application-thread/2497
**Category:** Help
**Created:** [January 9, 2021, 12:09pm UTC](https://discourse.jabref.org/t/javafx-application-thread/2497 "2021-01-09T12:09:26Z")
**Posts on this page:** 7
**Page:** 1

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### Author: ![philkaes](https://avatars.discourse-cdn.com/v4/letter/p/c77e96/32.png) [@philkaes](https://discourse.jabref.org/u/philkaes)
#### Post date: [January 9, 2021, 12:09pm UTC](https://discourse.jabref.org/t/javafx-application-thread/2497/1 "2021-01-09T12:09:26Z")

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Hey guys,

I’m completely new to JabRef and this forum so please be kind if I did something wrong. 😊

I created a custom entry type “online” due to there is no default entry type for online sources (or am I wrong?). Every time I try to fill in the fields (citation key, title, author, date (optional), url, urldate) I get the following error message:

 ![image](https://canada1.discourse-cdn.com/flex030/uploads/jabref/original/1X/32b5df1e7e60cb55bfe5a9d19575fecd6f86430c.png)

Can you please help me with this?

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### Author: ![Siedlerchr](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.jabref.org/siedlerchr/32/216_2.png) [@Siedlerchr](https://discourse.jabref.org/u/Siedlerchr)
#### Post date: [January 9, 2021, 4:48pm UTC](https://discourse.jabref.org/t/javafx-application-thread/2497/2 "2021-01-09T16:48:34Z")

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Hi,

if you change your library mode to biblatex you have an entry type online.

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### Author: ![philkaes](https://avatars.discourse-cdn.com/v4/letter/p/c77e96/32.png) [@philkaes](https://discourse.jabref.org/u/philkaes)
#### Post date: [January 9, 2021, 5:26pm UTC](https://discourse.jabref.org/t/javafx-application-thread/2497/3 "2021-01-09T17:26:58Z")

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Thank you for your answer. I changed the library mode to biblatex but unfortunately the error still occurs when I’m selecting the “{} BibTeX Source” after filling in the “online” fields.

So the problem is still unsolved.

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### Author: ![Siedlerchr](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.jabref.org/siedlerchr/32/216_2.png) [@Siedlerchr](https://discourse.jabref.org/u/Siedlerchr)
#### Post date: [January 9, 2021, 5:54pm UTC](https://discourse.jabref.org/t/javafx-application-thread/2497/4 "2021-01-09T17:54:27Z")

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Which jabref version are you using? 5.2? If not then update it

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### Author: ![philkaes](https://avatars.discourse-cdn.com/v4/letter/p/c77e96/32.png) [@philkaes](https://discourse.jabref.org/u/philkaes)
#### Post date: [January 9, 2021, 6:06pm UTC](https://discourse.jabref.org/t/javafx-application-thread/2497/5 "2021-01-09T18:06:00Z")

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Yes I’m using version 5.2. …

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### Author: ![Siedlerchr](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.jabref.org/siedlerchr/32/216_2.png) [@Siedlerchr](https://discourse.jabref.org/u/Siedlerchr)
#### Post date: [January 9, 2021, 6:29pm UTC](https://discourse.jabref.org/t/javafx-application-thread/2497/6 "2021-01-09T18:29:59Z")

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Can you please post the details of the exception?  
Just paste them here. That will help narrowing down the error

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### Author: ![philkaes](https://avatars.discourse-cdn.com/v4/letter/p/c77e96/32.png) [@philkaes](https://discourse.jabref.org/u/philkaes)
#### Post date: [January 10, 2021, 10:52am UTC](https://discourse.jabref.org/t/javafx-application-thread/2497/7 "2021-01-10T10:52:03Z")

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So I don’t know why but it seems like it’s working now. I will comment on this post again, if the error occurs again.

Thank you for your help!