diff --git a/.github/workflows/CI.yaml b/.github/workflows/CI.yaml
index 926454ee..54dd0f20 100644
--- a/.github/workflows/CI.yaml
+++ b/.github/workflows/CI.yaml
@@ -4,9 +4,11 @@ on:
   push:
     branches:
       - "main"
+      - "0-1-x"
   pull_request:
     branches:
       - "main"
+      - "0-1-x"
   schedule:
     - cron: "0 0 * * *"
 
diff --git a/openff/bespokefit/optimizers/forcebalance/forcebalance.py b/openff/bespokefit/optimizers/forcebalance/forcebalance.py
index 68aa75cc..79821b2b 100644
--- a/openff/bespokefit/optimizers/forcebalance/forcebalance.py
+++ b/openff/bespokefit/optimizers/forcebalance/forcebalance.py
@@ -168,6 +168,14 @@ def _read_output(cls, root_directory) -> Dict[str, Any]:
 
         result = {"error": None}
 
+        try:
+            with open(os.path.join(root_directory, "optimize.err")) as err:
+                errlog = err.read()
+                if "Traceback" in errlog:
+                    raise ValueError(f"ForceBalance job failed: {errlog}")
+        except IOError:
+            pass
+
         with open(os.path.join(root_directory, "optimize.out")) as log:
 
             for line in log.readlines():