diff --git a/src/synth_mapping_helper/__init__.py b/src/synth_mapping_helper/__init__.py
index 6ff2e8a..5a326f8 100644
--- a/src/synth_mapping_helper/__init__.py
+++ b/src/synth_mapping_helper/__init__.py
@@ -1,4 +1,4 @@
-__version__ = "1.5.4"
+__version__ = "1.5.5"
 
 from . import movement
 from . import pattern_generation
diff --git a/src/synth_mapping_helper/analysis.py b/src/synth_mapping_helper/analysis.py
index e233683..367fc74 100644
--- a/src/synth_mapping_helper/analysis.py
+++ b/src/synth_mapping_helper/analysis.py
@@ -150,7 +150,7 @@ def all_wall_densities(diffs: dict[str, DataContainer]) -> dict[str, dict[str, P
 
 def hand_curve(notes: SINGLE_COLOR_NOTES, window_b: float) -> HAND_CURVE_TYPE:
     if not notes:
-        return np.full((1,3), np.nan)
+        return np.full((1,3), np.nan), np.full((1,3), np.nan), np.full((1,3), np.nan)
     # step 1: find average positions for each time "bin", by weighted average of notes and (interpolated) rails
     data_points: dict[int, "numpy array (3,)"] = {}  # t//i: weight,x,y
     for _, nodes in sorted(notes.items()):
@@ -209,7 +209,11 @@ def _append_section():
     if current_curve:
         _append_section()
     # put it all together
-    return np.concatenate(out_curve), np.concatenate(out_vel), np.concatenate(out_acc)
+    return (
+        np.concatenate(out_curve),
+        np.concatenate(out_vel) if out_vel else np.full((1,3), np.nan),
+        np.concatenate(out_acc) if out_acc else np.full((1,3), np.nan)
+    )
 
 def hand_curves(data: DataContainer) -> dict[str, HAND_CURVE_TYPE]:
     return {
diff --git a/src/synth_mapping_helper/gui_tabs/utils.py b/src/synth_mapping_helper/gui_tabs/utils.py
index cd90409..e5dd4f1 100644
--- a/src/synth_mapping_helper/gui_tabs/utils.py
+++ b/src/synth_mapping_helper/gui_tabs/utils.py
@@ -30,6 +30,7 @@
 logger = logging.getLogger("SMH-GUI")
 wiki_base = "https://github.com/adosikas/synth_mapping_helper/wiki"
 
+start_time = datetime.datetime.now(datetime.timezone.utc)
 last_errors: list[tuple[str, Exception|None, Any, Any, datetime.datetime]] = []
 
 @dataclass
@@ -131,9 +132,11 @@ def render(self, content: Any) -> bytes:
 
 @app.get("/error_report", response_class=PrettyJSONResponse)
 def error_report():
+    now = datetime.datetime.now(datetime.timezone.utc)
     out = {
         "version": __version__,
-        "report_time": datetime.datetime.now(datetime.timezone.utc).strftime("%Y-%m-%dT%H-%M-%SZ"),
+        "report_time": now.strftime("%Y-%m-%dT%H-%M-%SZ"),
+        "runtime": str(datetime.timedelta(seconds=round((now-start_time).total_seconds()))),  # rounded to full seconds
         "errors": [],
     }
     for msg, exc, context, data, time in last_errors:
diff --git a/src/synth_mapping_helper/synth_format.py b/src/synth_mapping_helper/synth_format.py
index 1ec411a..76fdafa 100644
--- a/src/synth_mapping_helper/synth_format.py
+++ b/src/synth_mapping_helper/synth_format.py
@@ -498,9 +498,9 @@ class SynthFileMeta:
 
     def get_safe_name(self, audio_data: bytes) -> str:
         # editor tracks spectrum data by filename, so just append sha256 of content to filename
-        sha256_hash = sha256(audio_data).hexdigest()
-        # <name>_<hash:64 hexdigits>.<ext> or <name>.<ext>
-        m = re.match(r"(.*?)(?:_[0-9a-fA-F]{64})*\.([^.]*)$", self.audio_name)
+        sha256_hash = sha256(audio_data).hexdigest()[:8]
+        # <name>_<hash:8 to 64 hexdigits>.<ext> or <name>.<ext>
+        m = re.match(r"(.*?)(?:_[0-9a-fA-F]{8,64})*\.([^.]*)$", self.audio_name)
         if m:
             name, ext = m[1], m[2]
         else:  # should only happen if there is no dot in the filename