Null database not found

I am working with fibery API. When i update an entity in the fibery, i want to receive it via API. I got an error like this:

Error: {
“name”: “entity.error/schema-type-not-found”,
“message”: “null database was not found.”,
“data”: {
“top”: {
“error/name”: “entity.error/schema-type-not-found”,
“error/schema-version”: 18,
“type”: null,
“query”: {
“q/select”: [
“fibery/id”,
“fibery/creation-date”,
null
],
“q/order-by”: [
[
[
“fibery/creation-date”
],
“q/desc”
]
],
“q/limit”: 25
}
},

What could cause this problem and how can i solve it?
database_not_found

Have you double checked that the type (database) name you are using matches exactly the one in the schema? Note: the API calls are generally case-sensitive.

yes, it seems fine

Would you like to share the relevant part of the schema and the command that is causing the error

3