Announcement texts are no longer played

Hello,

I have successfully run a telephone system on a Raspi Asterisk 14.2.0 since 2016 successfully. For a few days, the announcement at the answering machine does not work anymore. Instead see in the Asterisk Cli this dialogue:

Asterisk Ready.
    -- Executing [071526929512@telekom_in:1] GotoIf("PJSIP/telekom_in-00000000", "0?unavail29512") in new stack
    -- Executing [071526929512@telekom_in:2] Dial("PJSIP/telekom_in-00000000", "PJSIP/29512&PJSIP/6001,20,m[To_of_us]") in new stack
[2019-02-07 09:50:50] ERROR[2863]: res_pjsip.c:2887 ast_sip_create_dialog_uac: Could not create dialog to endpoint '6001' as URI '6001' is not valid
[2019-02-07 09:50:50] ERROR[2863]: chan_pjsip.c:2146 request: Failed to create outgoing session to endpoint '6001'
[2019-02-07 09:50:50] WARNING[2920][C-00000001]: app_dial.c:2530 dial_exec_full: Unable to create channel of type 'PJSIP' (cause 3 - No route to destination)
    -- Called PJSIP/29512
    -- Started music on hold, class 'default', on channel 'PJSIP/telekom_in-00000000'
    -- PJSIP/29512-00000001 is ringing
    -- Contact 29512/sip:29512@192.168.0.24:5060;transport=udp is now Unknown.  RTT: 0.000 msec
    -- Nobody picked up in 20000 ms
    -- Stopped music on hold on PJSIP/telekom_in-00000000
    -- Executing [071526929512@telekom_in:3] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,6,jan?holiday1") in new stack
    -- Executing [071526929512@telekom_in:4] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,31,mar?holiday1") in new stack
    -- Executing [071526929512@telekom_in:5] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,2,apr?holiday1") in new stack
    -- Executing [071526929512@telekom_in:6] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,1,may?holiday1") in new stack
    -- Executing [071526929512@telekom_in:7] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,10,may?holiday1") in new stack
    -- Executing [071526929512@telekom_in:8] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,16,jun?bridgeday1") in new stack
    -- Executing [071526929512@telekom_in:9] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,21,may?holiday1") in new stack
    -- Executing [071526929512@telekom_in:10] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,31,may?holiday1") in new stack
    -- Executing [071526929512@telekom_in:11] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,2,oct?bridgeday1") in new stack
    -- Executing [071526929512@telekom_in:12] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,3,oct?holiday1") in new stack
    -- Executing [071526929512@telekom_in:13] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,31,oct?holiday1") in new stack
    -- Executing [071526929512@telekom_in:14] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,1,nov?holiday1") in new stack
    -- Executing [071526929512@telekom_in:15] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,25,dec?holiday1") in new stack
    -- Executing [071526929512@telekom_in:16] GotoIfTime("PJSIP/telekom_in-00000000", "08:00-9:59,*,26,dec?holiday1") in new stack
    -- Executing [071526929512@telekom_in:17] Playback("PJSIP/telekom_in-00000000", "Morgen") in new stack
    -- <PJSIP/telekom_in-00000000> Playing 'Morgen.slin' (language 'de')
       > 0x75f12b20 -- Probation passed - setting RTP source address to 217.0.5.150:32876
    -- Executing [071526929512@telekom_in:18] VoiceMail("PJSIP/telekom_in-00000000", "9512@Office,s") in new stack
    -- <PJSIP/telekom_in-00000000> Playing 'beep.slin' (language 'de')
    -- Recording the message
    -- x=0, open writing:  /var/spool/asterisk/voicemail/Office/9512/tmp/wsW10A format: wav, 0x75f26614
    -- User hung up
  == Parsing '/var/spool/asterisk/voicemail/Office/9512/INBOX/msg0003.txt': Found
  == Parsing '/var/spool/asterisk/voicemail/Office/9512/INBOX/msg0003.txt': Found
  == Spawn extension (telekom_in, 071526929512, 18) exited non-zero on 'PJSIP/telekom_in-00000000'

“Morgen.slin” is in “/var/lib/asterisk/sounds/de/” “Morgen.wav” and that had worked so far. The recording function of the answering machine is still working. Only the announcements are not played anymore.
Here is the corresponding part from the dialplan:

[telekom_in]
; Zeiten für Anrufbeantworter
include => morning-closed,06:00-7:59,mon-fri;*,*
include => morning,08:00-9:59,mon-fri;*,*
include => day,10:00-17:29,mon-fri;*,*
include => evening,17:30-17:59,mon-fri;*,*
include => evening-closed,18:00-20:59,mon-fri;*,*
include => night,21:00-5:59,mon-fri;*,*
include => weekend-morning,06:00-9:59,sat-sun;*,*
include => weekend-day,10:00-17:29,sat-sun;*,*
include => weekend-evening,17:30-20:59,sat-sun;*,*
include => weekend-night,21:00-5:59,sat-sun;*,*

;include => morning-closed
include => morning
include => day
include => evening
include => evening-closed
include => night
include => weekend-morning
include => weekend-day
include => weekend-evening
include => weekend-night

; Anrufe von extern via Telekom
[morning-closed]
exten => 071526929512,1,GotoIf($[${DEVICE_STATE(PJSIP/29512)}=UNAVAILABLE]?unavail29512)
 same => n,GotoIfTime(0:00-5:59,mon-fri,*,*?unavail29512)
 same => n,Dial(PJSIP/29512&PJSIP/6001,1)
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,6,jan?holiday1)                                     ;Neujahr
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,31,mar?holiday1)                                    ;Karfreitag 2018
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,2,apr?holiday1)                                     ;Ostermontag 2018
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,1,may?holiday1)                                     ;1.Mai
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,10,may?holiday1)                                    ;Himmelfahrt 2018
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,16,jun?bridgeday1)                                  ;Brückentag
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,21,may?holiday1)                                    ;Pfingstenmontag 2018
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,31,may?holiday1)                                    ;Fronleichnam 2018
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,2,oct?bridgeday1)                                   ;Brückentag
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,3,oct?holiday1)                                     ;Deutsche Einheit
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,31,oct?holiday1)                                    ;Reformationstag
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,1,nov?holiday1)                                     ;Allerheiligen
 same => n(unavail29512),GotoIfTime(06:00-7:59,*,25,dec?holiday1)                                    ;Weihnachten
 same  => n(unavail29512),GotoIfTime(06:00-7:59,*,26,dec?holiday1)                                    ;Weihnachten
 same => n,GotoIfTime(0:00-7:59,mon-fri,*,*?unavail29512)
 same => n(unavail29512),Playback(Closed-Morgen)
 same => n,VoiceMail(9512@Office,s)
 same => n,Hangup()
 same => n(holiday1),Playback(Holiday-Morgen)
 same => n,VoiceMail(9512@Office,s)
 same => n,Hangup()
 same => n(bridgeday1),Playback(BridgeDay-Morgen)
 same => n,VoiceMail(9512@Office,s)
 same => n,Hangup()
exten => 07117189517,1,GotoIf($[${DEVICE_STATE(PJSIP/89517)}=UNAVAILABLE]?unavail89517)
 same => n,Dial(PJSIP/89517&PJSIP/6001,20,m[To_of_us])
 same => n(unavail89517),Playback(privat-Morgen)
 same => n,VoiceMail(9517@Office,s)
 same => n,Hangup()

[morning]
exten => 071526929512,1,GotoIf($[${DEVICE_STATE(PJSIP/29512)}=UNAVAILABLE]?unavail29512)
 same => n,Dial(PJSIP/29512&PJSIP/6001,20,m[To_of_us])
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,6,jan?holiday1)                                     ;Neujahr
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,31,mar?holiday1)                                    ;Karfreitag 2018
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,2,apr?holiday1)                                     ;Ostermontag 2018
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,1,may?holiday1)                                     ;1.Mai
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,10,may?holiday1)                                    ;Himmelfahrt 2018
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,16,jun?bridgeday1)                                  ;Brückentag
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,21,may?holiday1)                                    ;Pfingstenmontag 2018
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,31,may?holiday1)                                    ;Fronleichnam 2018
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,2,oct?bridgeday1)                                   ;Brückentag
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,3,oct?holiday1)                                     ;Deutsche Einheit
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,31,oct?holiday1)                                    ;Reformationstag
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,1,nov?holiday1)                                     ;Allerheiligen
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,25,dec?holiday1)                                    ;Weihnachten
 same => n(unavail29512),GotoIfTime(08:00-9:59,*,26,dec?holiday1)                                    ;Weihnachten
 same => n,Playback(Morgen)
 same => n,VoiceMail(9512@Office,s)
 same => n,Hangup()
 same => n(holiday1),Playback(Holiday-Morgen)
 same => n,VoiceMail(9512@Office,s)
 same => n,Hangup()
 same => n(bridgeday1),Playback(BridgeDay-Morgen)
 same => n,VoiceMail(9512@Office,s)
 same => n,Hangup()
exten => 07117189517,1,GotoIf($[${DEVICE_STATE(PJSIP/89517)}=UNAVAILABLE]?unavail89517)
 same => n,Dial(PJSIP/89517&PJSIP/6001,20,m[To_of_us])
 same => n(unavail89517),Playback(privat-Morgen)
 same => n,VoiceMail(9517@Office,s)
 same => n,Hangup()

Do you can help me with a solution?

Thanks

Kaheto