Hi,

This is because you have invalid fields in your profile/group/event.

Please head over to backend and check custom fields under Profile Types, Group Categories and Event Categories to ensure that all the invalid fields are removed.

How I can't understand is fields invalid?

I checked Group Categories and Event Categories - there is no any fields in them.

I checked custom fields under Profile Types - all field looks fine - no any error or notifications...

Hi,

In that case then please do provide me:

1. FTP access
2. The user access that encounters this problem
3. Backend access

Access provided.
But this problem appears not allways, only sometimes.
And I can't understand why it happens and after what.

Hi,

Hmm I've manually checked your database and it seems like all data are correct.

Is this error still happening for you?

Yes, for my account, but not always.
Last hour I didn't seen it.
Maybe it fixed itself

Hmm probably but do let me know if this happens again.