Subject [fbserver 2.5.8] crash after recreation of Foreign Keys

Hello Support Team,

We are trying to launch an update on a relatively large database (1.5 Gb ) i.e ; inserting/deleting rows,

folowing these steps :

1) we DROP FK list

2) we insert/update/delete rows

3) recreate FK list

- the FK command list contains 477 FKs , atleast 50 FKs affects tables that already been affacted by other FK commands

- if we eleminate step 2 for testing reasons : everything goes well

- if we copy/paste the FK creation script on the IDE FlameRobin : it takes a long time, but it commits successfully.

- the problem is genrated after the update (atleast 50 thousand rows affected) : fbserver takes a long time to commit but it crashes , then FbGuardian restarts it .

- we tried the options : WAIT / NO WAIT and SET AUTODDL ON , or even Firebird 3.0 with no results

we got these error messages :

Unable to complete network request to host "localhost".Error reading data from the connection.

in the firebird log :

xxx (Client)    Mon Jul 23 12:55:07 2018
    REMOTE INTERFACE/gds__detach: Unsuccesful detach from database.
    Uncommitted work may have been lost

Windows 10 / mac OS X yosemite 10.10.5 both 64bits
firebird 2.5.8 (standard and debug)
We run  a ProcDump to help identify the problem (7z archive password :   firebird)