Problem with an item

Dear,
I have this 2 items in my knx.items file:

Color KNX_ILL_APP_RGB_SOGGIORNO
Color KNX_ILL_APP_RGB_SALA

When I restart openhab I recive this error:

2018-09-23 12:36:09.913 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:09.924 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:09.922 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:09.922 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:09.913 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:10.813 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:10.813 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:10.355 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:10.147 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:11.401 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:11.189 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20
2018-09-23 12:36:10.962 [ERROR] [ntime.internal.engine.RuleEngineImpl] - Rule 'Modifica colore bianco sala': The name 'KNX_ILL_APP_RGB_SALA' cannot be resolved to an item or type; line 40, column 5, length 20

The same error is not present for the specular rule.
In few words the items “KNX_ILL_APP_RGB_SOGGIORNO” has not problems, only the “KNX_ILL_APP_RGB_SALA” item seems to have problem, but I don’t understand why…

rule "Modifica colore bianco soggiorno"
  when
    Item KNX_ILL_APP_RGB_SOGGIORNO_W_ONOFF received command or
    Item KNX_ILL_APP_RGB_SOGGIORNO_W_DIMMER received command
  then
    KNX_ILL_APP_RGB_SOGGIORNO.postUpdate("0,0,0")
    KNX_ILL_APP_SOGGIORNO_RED.postUpdate("0")
    KNX_ILL_APP_SOGGIORNO_GREEN.postUpdate("0")
    KNX_ILL_APP_SOGGIORNO_BLU.postUpdate("0")
end

rule "Modifica colore bianco sala"
  when
    Item KNX_ILL_APP_RGB_SALA_W_ONOFF received command or
    Item KNX_ILL_APP_RGB_SALA_W_DIMMER received command
  then
    KNX_ILL_APP_RGB_SALA.postUpdate("0,0,0")
    KNX_ILL_APP_SALA_RED.postUpdate("0")
    KNX_ILL_APP_SALA_GREEN.postUpdate("0")
    KNX_ILL_APP_SALA_BLU.postUpdate("0")
end

can you help me?

thanks

post the contents of the file showing the definitions of these 2 items
try to change the name of the item and make sure you don’t have any typos