diff --git a/CHANGELOG.md b/CHANGELOG.md
index e3dece10..eecd1d90 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Change Log
 
+## Unreleased
+
+- Fix case where shell cannot be found for `add_process`.
+- Fix UTC compatibility for Python 3.10.
+- Added retrieval of server version in `Sender`.
+- Fixed memory issue when downloading large data files.
+- Fixed incorrect exception catch for JSON responses.
+
 ## [v2.5.9](https://github.com/simvue-io/python-api/releases/tag/v2.5.9) - 2026-06-26
 
 - Fixed bug with error handling in logging handler
diff --git a/simvue/executor.py b/simvue/executor.py
index 8fb3b31a..80339918 100644
--- a/simvue/executor.py
+++ b/simvue/executor.py
@@ -35,7 +35,7 @@ def __call__(self, *, status_code: int, std_out: str, std_err: str) -> None: ...
 
 
 def get_current_shell() -> str | None:
-    """Return the users current shell executable."""
+    """Return the users current shell executable if found."""
     try:
         _process = psutil.Process(os.getppid())
         return os.environ.get("SHELL", _process.exe())
@@ -156,7 +156,7 @@ def std_err(self, process_id: str) -> str | None:
     def _kwarg_assembly(kwargs, executable: str | None) -> list[str]:
         _arguments: list[str] = []
         _shell_is_pwsh: bool = any(
-            shell in get_current_shell() for shell in ("pwsh", "powershell")
+            shell in (get_current_shell() or "") for shell in ("pwsh", "powershell")
         )
         _exec_is_pwsh: bool = executable in {"pwsh", "powershell", None}
         _use_pwsh: bool = _shell_is_pwsh and _exec_is_pwsh