# Vapor is crashed while selecting new renderer and setting renderer name

**URL:** <https://vapor.discourse.group/t/vapor-is-crashed-while-selecting-new-renderer-and-setting-renderer-name/335>\
**Category:** Uncategorized\
**Created:** [October 26, 2023, 7:53am UTC](https://vapor.discourse.group/t/vapor-is-crashed-while-selecting-new-renderer-and-setting-renderer-name/335 "2023-10-26T07:53:55Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![muteldw](https://yyz2.discourse-cdn.com/free1/user_avatar/vapor.discourse.group/muteldw/32/132_2.png) [@muteldw](https://vapor.discourse.group/u/muteldw)\
**Post date:** [October 26, 2023, 7:53am UTC](https://vapor.discourse.group/t/vapor-is-crashed-while-selecting-new-renderer-and-setting-renderer-name/335/1 "2023-10-26T07:53:55Z")

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It’s crashed when I define variable with numbers only.

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**Author:** ![pearse](https://yyz2.discourse-cdn.com/free1/user_avatar/vapor.discourse.group/pearse/32/177_2.png) [@pearse](https://vapor.discourse.group/u/pearse)\
**Post date:** [October 26, 2023, 2:48pm UTC](https://vapor.discourse.group/t/vapor-is-crashed-while-selecting-new-renderer-and-setting-renderer-name/335/2 "2023-10-26T14:48:42Z")

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Hi, VAPOR uses XML to store its current state, which has the following restrictions:

```auto
    - Element names are case-sensitive 
    - Element names must start with a letter or underscore
    - Element names cannot start with the letters xml(or XML, or Xml, etc) 
    - Element names can contain letters, digits, hyphens, underscores, and periods 
    - Element names cannot contain spaces

```

However VAPOR should not be crashing. [We have a ticket for this](https://github.com/NCAR/VAPOR/issues/3471) that should be fixed in 3.9.1, which should be out before the end of the year.

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<div class="post-metadata">

**Author:** ![muteldw](https://yyz2.discourse-cdn.com/free1/user_avatar/vapor.discourse.group/muteldw/32/132_2.png) [@muteldw](https://vapor.discourse.group/u/muteldw)\
**Post date:** [November 17, 2023, 2:01am UTC](https://vapor.discourse.group/t/vapor-is-crashed-while-selecting-new-renderer-and-setting-renderer-name/335/3 "2023-11-17T02:01:00Z")

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Thanks a lot!  
It is very useful and helpful information.