# Trouble upgrade V16

**URL:** <https://www.dolibarr.org/forum/t/trouble-upgrade-v16/22751>\
**Category:** Installing my Dolibarr\
**Tags:** v16\
**Created:** [September 8, 2022, 7:59pm UTC](https://www.dolibarr.org/forum/t/trouble-upgrade-v16/22751 "2022-09-08T19:59:26Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![nemprinter](https://www.dolibarr.org/forum/user_avatar/www.dolibarr.org/nemprinter/32/433_2.png) [@nemprinter](https://www.dolibarr.org/forum/u/nemprinter)\
**Post date:** [September 8, 2022, 7:59pm UTC](https://www.dolibarr.org/forum/t/trouble-upgrade-v16/22751/1 "2022-09-08T19:59:26Z")

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i have upgrade my tryout server and that is on a 22.04 ubuntu but my standard server run 20.04 and it gives this error "Unknown column ‘u.national\_registration\_number’ in ‘field list’ "

shut i update to ubuntu 22.04

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**Author:** ![nemprinter](https://www.dolibarr.org/forum/user_avatar/www.dolibarr.org/nemprinter/32/433_2.png) [@nemprinter](https://www.dolibarr.org/forum/u/nemprinter)\
**Post date:** [September 9, 2022, 6:49am UTC](https://www.dolibarr.org/forum/t/trouble-upgrade-v16/22751/2 "2022-09-09T06:49:20Z")

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i have now upgrade to 22.04 and it is still same problem ? and it happens when i try to login to Dolibarr  
Tryout(Test) server it have been install with V17 alpha before and i just install V16 on top?  
that one is working

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**Author:** ![priojk](https://www.dolibarr.org/forum/user_avatar/www.dolibarr.org/priojk/32/6121_2.png) [@priojk](https://www.dolibarr.org/forum/u/priojk)\
**Post date:** [September 9, 2022, 7:27am UTC](https://www.dolibarr.org/forum/t/trouble-upgrade-v16/22751/4 "2022-09-09T07:27:07Z")

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It is not possible to downgrade the database from a higher version to a lower one. In order to test v16 after the installation of v17, you should do it with a new, empty database.

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**Author:** ![nemprinter](https://www.dolibarr.org/forum/user_avatar/www.dolibarr.org/nemprinter/32/433_2.png) [@nemprinter](https://www.dolibarr.org/forum/u/nemprinter)\
**Post date:** [September 9, 2022, 7:42am UTC](https://www.dolibarr.org/forum/t/trouble-upgrade-v16/22751/5 "2022-09-09T07:42:16Z")

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the one i have problem with is my main installation and the other one is my test setup and that one is running so i think it is some bug in standard setup probably something with my danish language

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**Author:** ![nemprinter](https://www.dolibarr.org/forum/user_avatar/www.dolibarr.org/nemprinter/32/433_2.png) [@nemprinter](https://www.dolibarr.org/forum/u/nemprinter)\
**Post date:** [September 15, 2022, 12:31pm UTC](https://www.dolibarr.org/forum/t/trouble-upgrade-v16/22751/6 "2022-09-15T12:31:03Z")

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Solved by install OS (Ubuntu 22.04.1) again and clean out all old things from Ubuntu 18.04 → 20.04