firebird - Error "invalid transaction handle (expecting explicit transaction start)" executing script from Delphi -

i'm developing update app delphi 10. i'm running windows 7 64x, firebird 2.5.1.26351 32x.

execution order:

• checks current version(select statement firebird database)
• downloads update(via ftp)
• apply it(.exe files, , execute .sql)

error code -901 pops out when try execute .sql files. know there incompatibility issue w7 64x , fdb 32x, but, can everything: backup , restore(gbak), db commands(all). tried fdb 64x instead, , not working.

code:

//components fdwaitcursor: tfdguixwaitcursor; fddriverlink: tfdphysfbdriverlink; fdconnection:tfdconnection; fdscript: tfdscript;  function tthr_script.createcomponents:boolean; begin   try   fddriverlink := tfdphysfbdriverlink.create(fddriverlink);   fdwaitcursor := tfdguixwaitcursor.create(fdwaitcursor);    fdconnection := tfdconnection.create(fdconnection);     fdconnection     begin       drivername := 'fb';       params.username := thrbanco.bduser;       params.password := thrbanco.bdpass;       params.database := thrbanco.dirorigem;     end;    fdscript := tfdscript.create(fdscript);     fdscript     begin       connection := fdconnection;       onconsoleput := fdscript_consoleput;     end;   result := true;   except on e:exception     begin       result := false;     end;   end; end;  procedure tthr_script.execlogs; var   f : integer;   sr : tsearchrec; begin   f := findfirst(extractfilepath(application.exename)+'\manager\update\logs\*.sql',faarchive,sr);   fdconnection.open;    while f = 0   begin     fdscript     begin       sqlscripts.clear;       sqlscriptfilename := extractfilepath(application.exename)+'\manager\update\logs\'+sr.name;       validateall;       executeall;     end;     application.processmessages;     f := findnext(sr);   end;   fdconnection.close; end; 

after installing firebird 2.5.6, still got same -901 error. error log:

update empresa set emp_verbanco='2016.55';  [13_09_2016 | 14:29]: ok [00:00:00.047].  [13_09_2016 | 14:29]: update empresa set emp_versis='2016.55';  [13_09_2016 | 14:29]: ok [00:00:00.016].  [13_09_2016 | 14:29]: commit work;  [13_09_2016 | 14:29]: error: dynamic sql error sql error code = -901 invalid transaction handle (expecting explicit transaction start) 

the error indicates having things 'commit work;' in sql script.

as per firedac documentation:

resolving incompatibilities

firebird isql works in non-autocommit mode. default, autocommit mode tfdscript/tfdconnection turned on. better compatibility, set fdconnection.txoptions.autocommit false before script execution. or execute set autocommit off script command.

http://docwiki.embarcadero.com/radstudio/berlin/en/executing_sql_scripts_(firedac)