Error 500 to account.name API requests after upgrade to v5.6

[Dmitry]

Request:
curl -g -H 'Espo-Authorization: <token>‘ -X GET "https://<crm server>/api/v1/Opportunity?where[0][field]=accountName&where[0][type]=equals&where[0][value]=<company name>"
worked before upgrading to 5.6.1 or 5.6.2 (can't determine). Now it returns HttpServerErrorException: 500 Internal Server Error

CRM Error Log:
Espo.ERROR: (42) SQLSTATE[42S22]: Column not found: 1054 Unknown column 'account.name' in 'where clause'; GET /api/v1/Opportunity?where[0][field]=accountName&where[0][type]=equals&where[0][value]=<company name>

[Dmitry]

Please respond. We have a critical integration broken because of that.

[item]

Hi,
look maybe here.. maybe same error :

https://github.com/espocrm/espocrm/commit/93553d18fcdf5fc5dd34ed80add662cb5be7d4b9

[Dmitry]

Hi,
look maybe here.. maybe same error :

https://github.com/espocrm/espocrm/commit/93553d18fcdf5fc5dd34ed80add662cb5be7d4b9

No, it didn't help.

[yuri]

We could not reproduce.

[Dmitry]

We could not reproduce.

The same error happens each time when trying to get a related entity by name, i.e. "find all Cases with a certain Contact Name". Below are some examples:

[2019-06-06 10:05:28] Espo.ERROR: (42) SQLSTATE[42S22]: Column not found: 1054 Unknown column 'account.name' in 'where clause'; GET /api/v1/Contact?where[0][field]=accountName&where[0][type]=equals&where[0][value]=Microsoft

[2019-06-06 10:08:44] Espo.ERROR: (42) SQLSTATE[42S22]: Column not found: 1054 Unknown column 'contact.first_name' in 'where clause'; GET /api/v1/Case?where[0][field]=contactName&where[0][type]=equals&where[0][value]=Bill+Gates

There seems to be some fault in the way this type of API requests are translated to SQL queries. And it only started after upgrading to v.5.6

[Dmitry]

Hi, what about the other errors I showed in my last message? Couldn't they be reproduced, too?