Problematic tests list (37 rows):
bugs.core_1746_test  Expression index can be created while doing inserts into table
bugs.core_1894_test  Circular dependencies between computed fields crash the engine
bugs.core_2140_test  Error messages after parameters substitution contains '\n' characters instead of line break
bugs.core_3450_test  Inefficient optimization (regression)
bugs.core_3610_test  Can insert DUPLICATE keys in UNIQUE index
bugs.core_3672_test  computed index by SUBSTRING function for long columns
bugs.core_3691_test  Missing constraint name in foreign key error message in FB 2.1.4
bugs.core_4386_test  Report more details for "object in use" errors
bugs.core_4754_test  Bugcheck 167 (invalid SEND request) while working with GTT from several attachments (using EXECUTE STATEMENT ... ON EXTERNAL and different roles)
bugs.core_4819_test  EXECUTE PROCEDURE's RETURNING_VALUES and EXECUTE STATEMENT's INTO does not check validity of assignments targets leading to bugcheck
bugs.core_4880_test  Better performance of creating packages containing many functions
bugs.core_4923_test  Add ability to track domains rename in DDL triggers
bugs.core_4933_test  Add better transaction control to isql
bugs.core_4937_test  View/subselect with "union" does not use computed index
bugs.core_5074_test  Lost the charset ID in selection of array element
bugs.core_5161_test  Unique index could be created on non-unique data
bugs.core_5410_test  Dependencies are not stored when using some type of contructions in subroutines
bugs.core_5481_test  Available indices are not used in some cases if ORDER BY expression is a filtered one
bugs.core_5488_session_idle_test  Timeouts for running SQL statements and idle connections
bugs.core_5606_test  Add expression index name to exception message if computation failed
bugs.core_5618_test  Part of the pages of the second level blobs is not released when deleting relations
bugs.core_5756_test  Regression: FB crashes when trying to recreate table that is in use by DML (3.0.3; 3.0.4; 4.0.0)
bugs.core_5843_test  Wrong handling of failures of TRANSACTION START trigger
bugs.core_5908_test  Enhance dynamic libraries loading related error messages
bugs.core_5921_test  Provide information about Global Commit Number, Commit Number of currently used database snapshot (if any) and Commit Numbers assigned to the committed transactions
bugs.core_6095_test  Extend trace record for COMMIT/ROLLBACK RETAINING to allow chaining of transaction ids
bugs.core_6252_test  UNIQUE / PRIMARY KEY constraint can be violated when AUTODDL = OFF and mixing commands for DDL and DML
bugs.core_6300_test  Next attachment id, next statement id and some other additions [CORE-6300]
bugs.core_6336_test  Regression in FB 4.x: error "Implementation of text subtype <NNNN> not located" on attempt to use some collations defined in fbintl.conf
bugs.core_6444_test  Ability to query Firebird configuration using SQL
bugs.gh_0310_test  System table with keywords
bugs.gh_3812_test  Query with SP doesn't accept explicit plan [CORE3451]
bugs.gh_6785_test  Problem when restoring the database on FB 4.0 RC1 (gbak regression)
bugs.gh_6869_test  Domain CHECK-expression can be ignored when we DROP objects that are involved in it
bugs.gh_7050_test  Add table MON$COMPILED_STATEMENTS and columns
bugs.gh_7062_test  Creation of expression index does not release its statement correctly
bugs.gh_7200_test  DROP DATABASE lead FB to hang if it is issued while DB encrypting/decrypting is in progress

This list is the same for:
6.0.0.1870 2026.04.01 7464f453  SS