diff --git a/parameters.yaml b/parameters.yaml
index 4d12005..4bc4d72 100644
--- a/parameters.yaml
+++ b/parameters.yaml
@@ -7,7 +7,7 @@ stations_blacklist: ["TEST", "EREA"]      # exclude these stations
 networks_blacklist: []                    # exclude these networks
 interval: 60               # Perform checks every x seconds
 n_track: 300               # wait n_track * intervals before performing an action (i.e. send mail/end highlight status)
-timespan: 1                # Check data of the recent x days
+timespan: 3                # Check data of the recent x days
 verbosity: 0               # verbosity flag
 track_changes: True        # tracks all changes since GUI startup by text highlighting (GUI only)
 warn_count: False           # show number of warnings and errors in table
@@ -125,7 +125,7 @@ add_links:
 # E-mail notifications
 EMAIL:
   mailserver: "localhost"
-  addresses: ["marcel.paffrath@rub.de",]# "kasper.fischer@rub.de"]  # list of mail addresses for info mails
+  addresses: ["marcel.paffrath@rub.de", "kasper.fischer@rub.de"]  # list of mail addresses for info mails
   sender: "webmaster@geophysik.ruhr-uni-bochum.de" # mail sender
   stations_blacklist: ['GR33']                     # do not send emails for specific stations
   networks_blacklist: []                           # do not send emails for specific network
diff --git a/simulate_fail.json b/simulate_fail.json
deleted file mode 100644
index 33bd01e..0000000
--- a/simulate_fail.json
+++ /dev/null
@@ -1,2 +0,0 @@
-{"1Y.GR01": "230V",
-"1Y.GR03":  "charger"}
\ No newline at end of file
diff --git a/survBot.py b/survBot.py
index 9cd5be1..44c2a8b 100755
--- a/survBot.py
+++ b/survBot.py
@@ -69,7 +69,7 @@ def get_nwst_id(trace):
 
 
 def fancy_timestr(dt, thresh=600, modif='+'):
-    if dt > timedelta(seconds=thresh):
+    if isinstance(dt, timedelta) and dt > timedelta(seconds=thresh):
         value = f'{modif} ' + str(dt) + f' {modif}'
     else:
         value = str(dt)
@@ -643,7 +643,7 @@ class StationQC(object):
         if n_errors is None:
             n_errors = self.parameters.get('n_track')
 
-        # +1 to check whether n_errors +1 was no error (error is new)
+        # +1 to check whether n_errors + 1 was no error (error is new)
         n_errors += 1
 
         # simulate an error specified in json file (dictionary: {nwst_id: key} )
@@ -657,6 +657,9 @@ class StationQC(object):
             # if first entry was no error but all others are, return True (-> new Fail n_track times)
             if not previous_errors[0] and all(previous_errors[1:]):
                 return True
+        # special case: n_errors set to 1 (+1) to check for upcoming error (refresh plot etc.), but not on startup
+        if not previous_errors[0] and n_errors == 2:
+            return True
         # in case previous_errors exists, last item is error but not all items are error, error still active
         elif previous_errors and previous_errors[-1] and not all(previous_errors):
             return 'active'
diff --git a/utils.py b/utils.py
index f433d9c..cacbb5d 100644
--- a/utils.py
+++ b/utils.py
@@ -47,10 +47,11 @@ def get_color_mpl(key):
 
 def get_time_delay_color(dt, dt_thresh):
     """ Set color of time delay after thresholds specified in self.dt_thresh """
-    if dt < dt_thresh[0]:
-        return get_color('OK')
-    elif dt_thresh[0] <= dt < dt_thresh[1]:
-        return get_color('WARN')
+    if isinstance(dt, type(dt_thresh[0])):
+        if dt < dt_thresh[0]:
+            return get_color('OK')
+        elif dt_thresh[0] <= dt < dt_thresh[1]:
+            return get_color('WARN')
     return get_color('FAIL')
 
 
diff --git a/write_utils.py b/write_utils.py
index c1ae268..d571c2a 100644
--- a/write_utils.py
+++ b/write_utils.py
@@ -55,7 +55,7 @@ def html_footer():
 
 
 def add_html_image(img_data, img_format='png'):
-    return f"""<br>\n<img src="data:image/{img_format};base64, {b64encode(img_data).decode('ascii')}">"""
+    return f"""<br>\n<img width="100%" src="data:image/{img_format};base64, {b64encode(img_data).decode('ascii')}">"""
 
 
 def get_html_row(items, html_key='td'):