diff --git a/.gitignore b/.gitignore
index 6a8a20f1..ea6c0962 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,3 +13,4 @@ duce.py
 new_enroll_test.py
 data.json
 gui-test.py
+.venv/
diff --git a/base.py b/base.py
index ed14ecb3..33367cc4 100644
--- a/base.py
+++ b/base.py
@@ -5,7 +5,7 @@
 import time
 import traceback
 from datetime import datetime, timezone
-from decimal import Decimal
+from decimal import Decimal, InvalidOperation
 from urllib.parse import parse_qs, unquote, urlparse, urlsplit, urlunparse
 
 import cloudscraper
@@ -740,29 +740,43 @@ def get_course_id(self, url):
         url = re.sub(r"\W+$", "", unquote(url))
         try:
             r = self.client.get(url)
+            r.raise_for_status()
         except requests.exceptions.ConnectionError:
             if self.debug:
-                print(r.text)
+                print("Connection error:", url)
             return "retry", url, False
+        except requests.exceptions.HTTPError as e:
+            if self.debug:
+                print(f"HTTP error {e.response.status_code}: {e}")
+            return "invalid", url, False
 
         soup = bs(r.content, "html5lib")
         if self.debug:
             with open("test/soup.html", "w", encoding="utf-8") as f:
                 f.write(str(soup))
-        course_id = soup.find("body").get("data-clp-course-id", "invalid")
-        if course_id == "invalid":
-            return "invalid", url, False
 
-        dma = json.loads(soup.find("body")["data-module-args"])
-        if self.debug:
-            with open("test/dma.json", "w") as f:
-                json.dump(dma, f, indent=4)
+        try:
+            dma = json.loads(soup.find("body")["data-module-args"])
+            if self.debug:
+                with open("test/dma.json", "w") as f:
+                    json.dump(dma, f, indent=4)
+            course_info = dma.get("serverSideProps", {}).get("course", None)
+            if not course_info:
+                if self.debug:
+                    print("Course information is missing in serverSideProps")
+                return "invalid", url, False
+
+            course_id = soup.find("body").get("data-clp-course-id", "invalid")
+            is_free = not course_info.get("isPaid", True)
+            if not self.debug and self.is_course_excluded(dma):
+                return "excluded", r.url, False
 
-        is_free = not dma["serverSideProps"]["course"].get("isPaid", True)
-        if not self.debug and self.is_course_excluded(dma):
-            return "excluded", r.url, False
+            return course_id, r.url, is_free
 
-        return course_id, r.url, is_free
+        except (KeyError, TypeError, json.JSONDecodeError):
+            if self.debug:
+                print("Error parsing course data:", traceback.format_exc())
+            return "invalid", url, False
 
     def is_course_excluded(self, dma):
         instructors = [
@@ -819,7 +833,13 @@ def check_course(self, course_id, coupon_code=None):
             status = r["redeem_coupon"]["discount_attempts"][0]["status"]
             coupon_valid = discount == 100 and status == "applied"
 
-        return Decimal(amount), coupon_valid
+        # can be "retry" or Decimal
+        try: 
+            amount = Decimal(amount)
+        except (InvalidOperation, ValueError):
+            amount = "retry" 
+
+        return amount, coupon_valid
 
     def start_enrolling(self):
         self.remove_duplicate_courses()