An unknown server error has occurred.

[Gustavo Buonnacorso]

when i try to create a new space i got: An unknown server error has occurred.

simple like that.

[edwin]

Hi @Gustavo Buonnacorso,

Take a look at this similar questions.

Confluence add Space fails

[Diego]

Hello there Gustavo!
I would like to start off by understanding a few points:

1- has this worked at some point in the past?
2- is this instance a new instance?
3- was there any change applied to the instance?
4- what database are you currently using?
5- which version of Confluence are you running?

The error reported is relatively known and seems to stem from problematic blueprints in your instance. Other customers had similar issues, like in this other Community thread:

- Unknown server error when trying to create a space

The steps provided there are the following:

Solution:

1- Backup database or even better the whole system ( VM snapshot / XM backup ). You better try this on your staging / dev system!
2- Shutdown Confluence
3- Delete tables:

DROP TABLE "AO_54C900_SPACE_BLUEPRINT_AO";
DROP TABLE "AO_54C900_C_TEMPLATE_REF";
DROP TABLE "AO_54C900_CONTENT_BLUEPRINT_AO";

4- Clean plugin cache: https://confluence.atlassian.com/confkb/how-to-clear-confluence-plugins-cache-297664846.html
5- Restart Confluence

Keep in mind that trying this workaround in a test environment is the best approach! Procedures that deal with your database directly must be treated with extra care. Knowing this, we strongly advise to always backup your database before touching it.

Please, let us know your thoughts on this!

[Felipe Santos]

1- has this worked at some point in the past?
yes, for 3 days worked.

2- is this instance a new instance?
new and fresh instance, with 3 days of years old

3- was there any change applied to the instance?
no, if had, was in configuration. Not in server envoiriment.

4- what database are you currently using?
mysql 5.7.24

5- which version of Confluence are you running?
6.12.2

Obs1)
when i try to delete -> AO_54C900_CONTENT_BLUEPRINT_AO
#1217 - Cannot delete or update a parent row: a foreign key constraint fails

Obs2) 
works, with only 2 tables removed.
now i acan add spaces again.