# Invalid License error message

**URL:** <https://community.tetra4d.com/t/invalid-license-error-message/334>\
**Category:** Tetra4D Converter\
**Created:** [November 22, 2022, 3:25pm UTC](https://community.tetra4d.com/t/invalid-license-error-message/334 "2022-11-22T15:25:40Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Tetra4DSupport](https://sea1.discourse-cdn.com/flex019/user_avatar/community.tetra4d.com/tetra4dsupport/32/188_2.png) [@Tetra4DSupport](https://community.tetra4d.com/u/Tetra4DSupport)\
**Post date:** [November 22, 2022, 3:25pm UTC](https://community.tetra4d.com/t/invalid-license-error-message/334/1 "2022-11-22T15:25:40Z")

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_I face the Invalid License error message when entering my license key / using Tetra4D trial version._

In recent Acrobat Pro versions (2020 and DC Continuous Relase) a new default option prevents most third party plug-ins from working correctly.

Please make sure that the default Adobe Acrobat Pro setting in Edit → Preferences → Security (Enhanced) → “ **Enable Protected Mode at startup** ” is DISABLED. Then restart Acrobat and enter your license key if asked to.

 ![00_acrobatEnhancedSecurity](https://us1.discourse-cdn.com/flex019/uploads/tetra4d/original/1X/f1485bcff27c30e6a86b6d1210ce17d88fe64165.png)

If you still face the error message please contact the [Support Team](https://tetra4d.com/learning/).

Regards,  
Tetra4D Support Team

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<div class="post-metadata">

**Author:** ![Tetra4DSupport](https://sea1.discourse-cdn.com/flex019/user_avatar/community.tetra4d.com/tetra4dsupport/32/188_2.png) [@Tetra4DSupport](https://community.tetra4d.com/u/Tetra4DSupport)\
**Post date:** [November 23, 2022, 2:23pm UTC](https://community.tetra4d.com/t/invalid-license-error-message/334/4 "2022-11-23T14:23:10Z")

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