diff --git a/src/alchemlyb/convergence/convergence.py b/src/alchemlyb/convergence/convergence.py
index 725231e2..d613f22e 100644
--- a/src/alchemlyb/convergence/convergence.py
+++ b/src/alchemlyb/convergence/convergence.py
@@ -46,6 +46,10 @@ def forward_backward_convergence(
         bigger than the error tolerance, the bootstrap error will be used.
 
         .. versionadded:: 2.3.0
+        .. versionchanged:: 2.4.0
+           Clarified docstring, removed incorrect estimation of std for cumulative
+           result in bar and added check that only a single lambda state is 
+           represented in the indices of each df in df_list.
 
     kwargs : dict
         Keyword arguments to be passed to the estimator.
diff --git a/src/alchemlyb/estimators/bar_.py b/src/alchemlyb/estimators/bar_.py
index d5b2c527..52353064 100644
--- a/src/alchemlyb/estimators/bar_.py
+++ b/src/alchemlyb/estimators/bar_.py
@@ -54,6 +54,9 @@ class BAR(BaseEstimator, _EstimatorMixOut):
 
     .. versionchanged:: 1.0.0
        `delta_f_`, `d_delta_f_`, `states_` are view of the original object.
+    .. versionchanged:: 2.4.0
+       Added assessment of lambda states represented in the indices of u_nk
+       to provide meaningful errors to ensure proper use.
 
     """
 
diff --git a/src/alchemlyb/estimators/mbar_.py b/src/alchemlyb/estimators/mbar_.py
index d0a2b31e..fa399cb1 100644
--- a/src/alchemlyb/estimators/mbar_.py
+++ b/src/alchemlyb/estimators/mbar_.py
@@ -79,6 +79,11 @@ class MBAR(BaseEstimator, _EstimatorMixOut):
         default value for `method` was changed from "hybr" to "robust"
     .. versionchanged:: 2.1.0
         `n_bootstraps` option added.
+    .. versionchanged:: 2.4.0
+       Handle initial estimate, initial_f_k, from bar in the instance
+       that not all lambda states represented as column headers are 
+       represented in the indices of u_nk.
+    
     """
 
     def __init__(
@@ -135,11 +140,6 @@ def fit(self, u_nk):
             )
             bar.fit(u_nk)
             initial_f_k = bar.delta_f_.iloc[0, :]
-            states = [
-                x
-                for i, x in enumerate(self._states_[:-1])
-                if N_k[i] > 0 and N_k[i + 1] > 0
-            ]
             if len(bar.delta_f_.iloc[0, :]) != len(self._states_):
                 states = [
                     x
diff --git a/src/alchemlyb/visualisation/convergence.py b/src/alchemlyb/visualisation/convergence.py
index 7d04a2e0..bf232b5d 100644
--- a/src/alchemlyb/visualisation/convergence.py
+++ b/src/alchemlyb/visualisation/convergence.py
@@ -56,11 +56,10 @@ def plot_convergence(dataframe, units=None, final_error=None, ax=None):
          Keyword arg final_error for plotting a horizontal error bar.
          The array input has been deprecated.
          The units default to `None` which uses the units in the input.
-
      .. versionchanged:: 0.6.0
          data now takes in dataframe
-
      .. versionadded:: 0.4.0
+     
     """
     if units is not None:
         dataframe = get_unit_converter(units)(dataframe)
@@ -193,6 +192,7 @@ def plot_block_average(dataframe, units=None, final_error=None, ax=None):
      `Alchemical Analysis <https://github.com/MobleyLab/alchemical-analysis>`_.
 
      .. versionadded:: 2.4.0
+     
     """
     if units is not None:
         dataframe = get_unit_converter(units)(dataframe)