# Problem with adding new custom block types (since V9.1)

**URL:** <https://forums.concretecms.org/t/problem-with-adding-new-custom-block-types-since-v9-1/3135>\
**Category:** Developing with Concrete\
**Created:** [May 30, 2022, 5:20am UTC](https://forums.concretecms.org/t/problem-with-adding-new-custom-block-types-since-v9-1/3135 "2022-05-30T05:20:28Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![PAlgoed](https://forums.concretecms.org/user_avatar/forums.concretecms.org/palgoed/32/3495_2.png) [@PAlgoed](https://forums.concretecms.org/u/PAlgoed)\
**Post date:** [May 30, 2022, 5:20am UTC](https://forums.concretecms.org/t/problem-with-adding-new-custom-block-types-since-v9-1/3135/1 "2022-05-30T05:20:28Z")

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in 9.1.0 (and 9.1.1) adding a custom block results in an error “undefined variable $…” for the first block variable used in the form (shared form for view, edit, add). editing existing blocks works fine. the problem is there for ALL custom block types.

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**Author:** ![Parasek](https://forums.concretecms.org/user_avatar/forums.concretecms.org/parasek/32/6277_2.png) [@Parasek](https://forums.concretecms.org/u/Parasek)\
**Post date:** [May 30, 2022, 12:32pm UTC](https://forums.concretecms.org/t/problem-with-adding-new-custom-block-types-since-v9-1/3135/2 "2022-05-30T12:32:06Z")

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I guess it’s not a problem with Concrete itself, but you probably updated php version to 8+ on your server. Undefined variables (often in custom blocks) are common error that need to be fixed before switching to php8.