diff --git a/check_apache_requests b/check_apache_requests
index 825d5cc4b7708321a2ebe54239cc263a49d95a83..89ba184d2269f6ba4f6f44477695ee374e012cd2 100755
--- a/check_apache_requests
+++ b/check_apache_requests
@@ -7,6 +7,7 @@
 # script checks output of "/server-status" and counts scoreboard chars
 # ----------------------------------------------------------------------
 # 2020-04-09  v1.0  <axel.hahn@iml.unibe.ch>
+# 2021-03-11  v1.1  <axel.hahn@iml.unibe.ch>  more error checks for output data
 # ======================================================================
 
 . `dirname $0`/inc_pluginfunctions
@@ -38,11 +39,10 @@ ph.require wget
 # --- get /server-status page
 wget --no-check-certificate -O $tmpfile $url 2>/dev/null
 if [ $? -ne 0 ]; then
-    ph.abort "UNKNOWN: url $url did not respond a server status. `wget --no-check-certificate -O - -S $url`"
-	exit 1
+    rm -f $tmpfile
+    ph.abort "UNKNOWN: request to url $url failed. `wget --no-check-certificate -O - -S $url`"
 fi
 
-
 # set default / override from command line params
 typeset -i iWarnLimit=`     ph.getValueWithParam 75 w "$@"`
 typeset -i iCriticalLimit=` ph.getValueWithParam 90 c "$@"`
@@ -52,6 +52,11 @@ typeset -i iCriticalLimit=` ph.getValueWithParam 90 c "$@"`
 iStart=` grep -n '<pre>'  $tmpfile | cut -f 1 -d ':'`
 iEnd=`   grep -n '</pre>' $tmpfile | cut -f 1 -d ':'`
 
+if [ $iStart -eq 0 -o $iEnd -eq 0 ]; then
+    rm -f $tmpfile
+    ph.abort "UNKNOWN: url $url has no PRE tag for apache scroreboard. I guess it is not a server-status page."
+fi
+
 sed -n "${iStart},${iEnd}p" $tmpfile | sed 's#<.*>##g' | tr -d "\n" >$tmpfile2
 
 # <p>Scoreboard Key:<br />
@@ -73,6 +78,11 @@ sed -n "${iStart},${iEnd}p" $tmpfile | sed 's#<.*>##g' | tr -d "\n" >$tmpfile2
 # total slots available
 iSlots=`cat $tmpfile2 | wc -m`
 
+if [ $iSlots -eq 0 ]; then
+    rm -f $tmpfile $tmpfile2
+    ph.abort "UNKNOWN: url $url has no count of slots. I guess it is not a server-status page or option for Extended status is off."
+fi
+
 # running apache processes waiting for a request
 iIdle=iCount=`sed -e "s/[^_]//g" $tmpfile2 | wc -m`