diff --git a/sonoff/_releasenotes.ino b/sonoff/_releasenotes.ino
index 72b5f1901..034877a45 100644
--- a/sonoff/_releasenotes.ino
+++ b/sonoff/_releasenotes.ino
@@ -3,7 +3,6 @@
  * Add random window to timers (#2447)
  * Add optional KNX IP Protocol Support (#2402)
  * Fix compile error when using ESP/Arduino library v2.3.0 by reverting KNX async UDP library to default UDP library (#2488,#2492,#2493)
- * Fix configuration filename truncation when it contains spaces (#2484, #2490)
  *
  * 5.12.0l
  * Release rules up to 511 characters
diff --git a/sonoff/support.ino b/sonoff/support.ino
index acff35224..4d1e51516 100644
--- a/sonoff/support.ino
+++ b/sonoff/support.ino
@@ -78,6 +78,72 @@ String GetResetReason()
   }
 }
 
+#ifdef DEBUG_THEO
+void ExceptionTest(byte type)
+{
+/*
+Exception (28):
+epc1=0x4000bf64 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000007 depc=0x00000000
+
+ctx: cont
+sp: 3fff1f30 end: 3fff2840 offset: 01a0
+
+>>>stack>>>
+3fff20d0:  202c3573 756f7247 2c302070 646e4920
+3fff20e0:  40236a6e 7954202c 45206570 00454358
+3fff20f0:  00000010 00000007 00000000 3fff2180
+3fff2100:  3fff2190 40107bfc 3fff3e4c 3fff22c0
+3fff2110:  40261934 000000f0 3fff22c0 401004d8
+3fff2120:  40238fcf 00000050 3fff2100 4021fc10
+3fff2130:  3fff32bc 4021680c 3ffeade1 4021ff7d
+3fff2140:  3fff2190 3fff2180 0000000c 7fffffff
+3fff2150:  00000019 00000000 00000000 3fff21c0
+3fff2160:  3fff23f3 3ffe8e08 00000000 4021ffb4
+3fff2170:  3fff2190 3fff2180 0000000c 40201118
+3fff2180:  3fff21c0 0000003c 3ffef840 00000007
+3fff2190:  00000000 00000000 00000000 40201128
+3fff21a0:  3fff23f3 000000f1 3fff23ec 4020fafb
+3fff21b0:  3fff23f3 3fff21c0 3fff21d0 3fff23f6
+3fff21c0:  00000000 3fff23fb 4022321b 00000000
+
+Exception 28: LoadProhibited: A load referenced a page mapped with an attribute that does not permit loads
+Decoding 14 results
+0x40236a6e: ets_vsnprintf at ?? line ?
+0x40107bfc: vsnprintf at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\cores\esp8266/libc_replacements.c line 387
+0x40261934: bignum_exptmod at ?? line ?
+0x401004d8: malloc at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\cores\esp8266\umm_malloc/umm_malloc.c line 1664
+0x40238fcf: wifi_station_get_connect_status at ?? line ?
+0x4021fc10: operator new[](unsigned int) at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\cores\esp8266/abi.cpp line 57
+0x4021680c: ESP8266WiFiSTAClass::status() at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\libraries\ESP8266WiFi\src/ESP8266WiFiSTA.cpp line 569
+0x4021ff7d: vsnprintf_P(char*, unsigned int, char const*, __va_list_tag) at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\cores\esp8266/pgmspace.cpp line 146
+0x4021ffb4: snprintf_P(char*, unsigned int, char const*, ...) at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\cores\esp8266/pgmspace.cpp line 146
+0x40201118: atol at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\cores\esp8266/core_esp8266_noniso.c line 45
+0x40201128: atoi at C:\Data2\Arduino\arduino-1.8.1-esp-2.3.0\portable\packages\esp8266\hardware\esp8266\2.3.0\cores\esp8266/core_esp8266_noniso.c line 45
+0x4020fafb: MqttDataHandler(char*, unsigned char*, unsigned int) at R:\Arduino\Work-ESP8266\Theo\sonoff\sonoff-4\sonoff/sonoff.ino line 679 (discriminator 1)
+0x4022321b: pp_attach at ?? line ?
+
+00:00:08 MQTT: tele/sonoff/INFO3 = {"Started":"Fatal exception:28 flag:2 (EXCEPTION) epc1:0x4000bf64 epc2:0x00000000 epc3:0x00000000 excvaddr:0x00000007 depc:0x00000000"}
+*/
+  if (1 == type) {
+    char svalue[10];
+    snprintf_P(svalue, sizeof(svalue), PSTR("%s"), 7);  // Exception 28 as number in string (7 in excvaddr)
+  }
+/*
+14:50:52 osWatch: FreeRam 25896, rssi 68, last_run 0
+14:51:02 osWatch: FreeRam 25896, rssi 58, last_run 0
+14:51:03 CMND: exception 2
+14:51:12 osWatch: FreeRam 25360, rssi 60, last_run 8771
+14:51:22 osWatch: FreeRam 25360, rssi 62, last_run 18771
+14:51:32 osWatch: FreeRam 25360, rssi 62, last_run 28771
+14:51:42 osWatch: FreeRam 25360, rssi 62, last_run 38771
+14:51:42 osWatch: Warning, loop blocked. Restart now
+*/
+  if (2 == type) {
+    while(1) delay(1000);  // this will trigger the os watch
+  }
+}
+#endif  // DEBUG_THEO
+
 /*********************************************************************************************\
  * Miscellaneous
 \*********************************************************************************************/
@@ -232,16 +298,6 @@ char* UpperCase_P(char* dest, const char* source)
   return dest;
 }
 
-char* SpaceToUnderscore(char* source)
-{
-  char* ptr = source;
-  while (*ptr) {
-    if (*ptr == ' ') { *ptr = '_'; }
-    ptr++;
-  }
-  return source;
-}
-
 boolean ParseIp(uint32_t* addr, const char* str)
 {
   uint8_t *part = (uint8_t*)addr;
diff --git a/sonoff/webserver.ino b/sonoff/webserver.ino
index b1e322648..38198826e 100644
--- a/sonoff/webserver.ino
+++ b/sonoff/webserver.ino
@@ -1001,7 +1001,7 @@ void HandleBackupConfiguration()
   WebServer->setContentLength(sizeof(buffer));
 
   char attachment[100];
-  snprintf_P(attachment, sizeof(attachment), PSTR("attachment; filename=Config_%s_%s.dmp"), SpaceToUnderscore(Settings.friendlyname[0]), my_version);
+  snprintf_P(attachment, sizeof(attachment), PSTR("attachment; filename=Config_%s_%s.dmp"), Settings.friendlyname[0], my_version);
   WebServer->sendHeader(F("Content-Disposition"), attachment);
   WebServer->send(200, FPSTR(HDR_CTYPE_STREAM), "");
   memcpy(buffer, &Settings, sizeof(buffer));