# Installation Error

**URL:** <https://forum.manager.io/t/installation-error/28126>\
**Category:** Uncategorized\
**Created:** [May 7, 2020, 2:15pm UTC](https://forum.manager.io/t/installation-error/28126 "2020-05-07T14:15:38Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![peternazmy](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.manager.io/peternazmy/32/24549_2.png) [@peternazmy](https://forum.manager.io/u/peternazmy)\
**Post date:** [May 7, 2020, 2:15pm UTC](https://forum.manager.io/t/installation-error/28126/1 "2020-05-07T14:15:38Z")

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Dear Manger Technical support team,

we need your help to fix the following installation Error my college is trying to install the Desktop edition and every time she getting the following Error

20.5.7:System Missing Method Exception: Method not found: ‘!!0  
system.Array.Empty()’.  
at Manager.Application Data.Get (Guide entityId)  
at Manager Desktop.Program.Main(Stringargs)

appreciate your help ASAP

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**Author:** ![Tut](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.manager.io/tut/32/3286_2.png) [@Tut](https://forum.manager.io/u/Tut)\
**Post date:** [May 7, 2020, 2:36pm UTC](https://forum.manager.io/t/installation-error/28126/2 "2020-05-07T14:36:06Z")

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See [Unable to launch Manager](https://forum.manager.io/t/unable-to-launch-manager/28119).

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**Author:** ![Ealfardan](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.manager.io/ealfardan/32/63166_2.png) [@Ealfardan](https://forum.manager.io/u/Ealfardan)\
**Post date:** [January 18, 2023, 2:55pm UTC](https://forum.manager.io/t/installation-error/28126/3 "2023-01-18T14:55:37Z")

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