diff --git a/config/visidata/visidatarc b/config/visidata/visidatarc
index 90ad6e6..7c602f5 100644
--- a/config/visidata/visidatarc
+++ b/config/visidata/visidatarc
@@ -1,7 +1,16 @@
-# copy or link this file to ~/.visidatarc
+# Install targets (VisiData v3.3):
+# - macOS default:  ~/Library/Preferences/visidata/config.py
+# - XDG default:    ${XDG_CONFIG_HOME:-~/.config}/visidata/config.py
+# - legacy fallback:~/.visidatarc
 options.disp_date_fmt="%Y-%m-%dT%H:%M:%S"
 
-import plugins.hidecol
+# User plugins are typically under $VD_DIR/plugins (default ~/.visidata/plugins).
+# VisiData adds $VD_DIR to sys.path, so they import as `plugins.<name>`.
+# Keep local/custom plugins optional so missing files don't break startup.
+try:
+    import plugins.hidecol
+except ModuleNotFoundError:
+    pass
 
 from datetime import datetime
 import functools
@@ -14,14 +23,26 @@ import pickle
 import time
 import sqlite3
 
+# VisiData loads the config via exec(code, vd.getGlobals(), newdefs).
+# Functions defined here capture vd.getGlobals() as their global namespace, but
+# `import ...` statements assign into `newdefs` (locals). Export key imports into
+# the real globals dict so decorators and function bodies can resolve them.
+globals().update({
+    'datetime': datetime,
+    'functools': functools,
+    'json': json,
+    'unquote_plus': unquote_plus,
+    'os': os,
+    'pickle': pickle,
+    'time': time,
+    'sqlite3': sqlite3,
+})
+
 cache_path = os.path.expanduser('~/.visidata_cache.db')
 
-def init_cache_db():
-    with sqlite3.connect(cache_path) as conn:
-        conn.execute('''CREATE TABLE IF NOT EXISTS cache
-                     (key TEXT PRIMARY KEY, value BLOB, timestamp INTEGER)''')
-
-init_cache_db()
+def _ensure_cache_db(conn):
+    conn.execute('''CREATE TABLE IF NOT EXISTS cache
+                 (key TEXT PRIMARY KEY, value BLOB, timestamp INTEGER)''')
 
 def disk_cache_decorator(max_age=None, lru_cache_size=1000):
     def decorator(func):
@@ -29,6 +50,7 @@ def disk_cache_decorator(max_age=None, lru_cache_size=1000):
         def get_from_sqlite(*args, **kwargs):
             key = f"{func.__name__}:{str(args)}:{str(kwargs)}"
             with sqlite3.connect(cache_path) as conn:
+                _ensure_cache_db(conn)
                 cursor = conn.cursor()
                 cursor.execute('SELECT value, timestamp FROM cache WHERE key=?', (key,))
                 row = cursor.fetchone()
@@ -53,16 +75,38 @@ def what(item):
     return f"{type(item)}:{str(item)}"
 
 def avgdiff(values):
-    L = sorted(values)
+    # Average absolute delta between adjacent sorted values.
+    # Return None for <2 values to avoid ZeroDivisionError and to render blank in VisiData.
+    nums = []
+    for v in values:
+        if v in (None, "", "null"):
+            continue
+        try:
+            nums.append(float(v))
+        except Exception:
+            continue
+    L = sorted(nums)
+    if len(L) < 2:
+        return None
     a = L[1:]
     b = L[:-1]
-    c = sum([abs(x[0]-x[1]) for x in zip(a,b)])
+    c = sum([abs(x[0]-x[1]) for x in zip(a, b)])
     return c/len(a)
 
 vd.aggregator('avgdiff', avgdiff)
 
 def distinct_list(values):
-    return [x for x in set(values)]
+    # Deterministic order for stable display: preserve first-seen order.
+    seen = set()
+    out = []
+    for v in values:
+        if v in (None, "", "null"):
+            continue
+        if v in seen:
+            continue
+        seen.add(v)
+        out.append(v)
+    return out
 
 vd.aggregator('distinct_list', distinct_list)
 
@@ -155,7 +199,11 @@ def dns_lookup(domain, record='A'):
     try:
         import dns
         import dns.resolver as rs
-        result = rs.query(domain, record)
+        # dnspython 2.x prefers resolve(); keep a fallback for older versions.
+        try:
+            result = rs.resolve(domain, record)
+        except AttributeError:
+            result = rs.query(domain, record)
         return ",".join([x.to_text() for x in result])
     except dns.resolver.NoAnswer as e:
         return ""
@@ -188,10 +236,10 @@ def _asn(ip):
 @functools.lru_cache(maxsize=1000)
 def asn(ip, type="asn"):
     if len(ip.split(",")) > 1:
-        return ",".join([_asn(x, type) for x in ip.split(",")])
+        return ",".join([asn(x.strip(), type) for x in ip.split(",") if x.strip()])
     try:
         record = _asn(ip)
-        return f'({record["asn"]}:{record["name"]}[{record["country"]}]'
+        return f'({record["asn"]}:{record["name"]}[{record["country"]}])'
     except:
         return ""
 
@@ -314,7 +362,15 @@ def int2ip(zahl):
 
 # convert IP-String to Integer
 def ip2int(ip):
-    return int.from_bytes(b"".join([int(c).to_bytes(1,'big') for c in b.split('.')]),'big')
+    try:
+        parts = [int(c) for c in str(ip).split(".")]
+        if len(parts) != 4:
+            return None
+        if any(p < 0 or p > 255 for p in parts):
+            return None
+        return int.from_bytes(bytes(parts), "big")
+    except Exception:
+        return None
 
 # parse KeyValue
 def dirty_kv(data):
@@ -324,6 +380,18 @@ def dirty_kv(data):
     
 
 # parse json with missing quotes around attribute names
-import yaml
+try:
+    import yaml
+except ModuleNotFoundError:
+    yaml = None
+
+globals()['yaml'] = yaml
+
 def dirty_json(data):
-    return yaml.load(data, yaml.SafeLoader)
\ No newline at end of file
+    if yaml is None:
+        return None
+    # yaml.safe_load can handle many "almost-json" payloads.
+    try:
+        return yaml.safe_load(data)
+    except Exception:
+        return None