diff --git a/src/gui_qt/_py/fitfuncwidget.py b/src/gui_qt/_py/fitfuncwidget.py
index 38fa341..5a621e5 100644
--- a/src/gui_qt/_py/fitfuncwidget.py
+++ b/src/gui_qt/_py/fitfuncwidget.py
@@ -1,10 +1,11 @@
 # -*- coding: utf-8 -*-
 
-# Form implementation generated from reading ui file 'resources/_ui/fitfuncwidget.ui'
+# Form implementation generated from reading ui file 'src/resources/_ui/fitfuncwidget.ui'
 #
-# Created by: PyQt5 UI code generator 5.12.3
+# Created by: PyQt5 UI code generator 5.15.7
 #
-# WARNING! All changes made in this file will be lost!
+# WARNING: Any manual changes made to this file will be lost when pyuic5 is
+# run again.  Do not edit this file unless you know what you are doing.
 
 
 from PyQt5 import QtCore, QtGui, QtWidgets
@@ -13,7 +14,12 @@ from PyQt5 import QtCore, QtGui, QtWidgets
 class Ui_FormFit(object):
     def setupUi(self, FormFit):
         FormFit.setObjectName("FormFit")
-        FormFit.resize(292, 477)
+        FormFit.resize(308, 477)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.MinimumExpanding, QtWidgets.QSizePolicy.Preferred)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(FormFit.sizePolicy().hasHeightForWidth())
+        FormFit.setSizePolicy(sizePolicy)
         self.verticalLayout = QtWidgets.QVBoxLayout(FormFit)
         self.verticalLayout.setContentsMargins(0, 0, 0, 0)
         self.verticalLayout.setSpacing(3)
@@ -33,7 +39,7 @@ class Ui_FormFit(object):
         self.scrollArea.setWidgetResizable(True)
         self.scrollArea.setObjectName("scrollArea")
         self.scrollwidget = QtWidgets.QWidget()
-        self.scrollwidget.setGeometry(QtCore.QRect(0, 0, 284, 442))
+        self.scrollwidget.setGeometry(QtCore.QRect(0, 0, 304, 444))
         self.scrollwidget.setObjectName("scrollwidget")
         self.scrollArea.setWidget(self.scrollwidget)
         self.verticalLayout_2.addWidget(self.scrollArea)
@@ -43,6 +49,12 @@ class Ui_FormFit(object):
         self.verticalLayout_3 = QtWidgets.QVBoxLayout(self.data_tab)
         self.verticalLayout_3.setObjectName("verticalLayout_3")
         self.comboBox = QtWidgets.QComboBox(self.data_tab)
+        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Fixed)
+        sizePolicy.setHorizontalStretch(0)
+        sizePolicy.setVerticalStretch(0)
+        sizePolicy.setHeightForWidth(self.comboBox.sizePolicy().hasHeightForWidth())
+        self.comboBox.setSizePolicy(sizePolicy)
+        self.comboBox.setMaximumSize(QtCore.QSize(288, 16777215))
         self.comboBox.setObjectName("comboBox")
         self.verticalLayout_3.addWidget(self.comboBox)
         self.scrollArea2 = QtWidgets.QScrollArea(self.data_tab)
@@ -52,7 +64,7 @@ class Ui_FormFit(object):
         self.scrollArea2.setWidgetResizable(True)
         self.scrollArea2.setObjectName("scrollArea2")
         self.scrollwidget2 = QtWidgets.QWidget()
-        self.scrollwidget2.setGeometry(QtCore.QRect(0, 0, 272, 357))
+        self.scrollwidget2.setGeometry(QtCore.QRect(0, 0, 286, 393))
         self.scrollwidget2.setObjectName("scrollwidget2")
         self.scrollArea2.setWidget(self.scrollwidget2)
         self.verticalLayout_3.addWidget(self.scrollArea2)
diff --git a/src/gui_qt/fit/fit_parameter.py b/src/gui_qt/fit/fit_parameter.py
index 1027519..bcb3d1f 100644
--- a/src/gui_qt/fit/fit_parameter.py
+++ b/src/gui_qt/fit/fit_parameter.py
@@ -263,6 +263,8 @@ class QFitParameterWidget(QtWidgets.QWidget, Ui_FormFit):
         return data_parameter, lb, ub, is_fixed, global_p, is_linked
 
     def set_parameter(self, set_id: str | None, parameter: list[float]) -> int:
+        param_len = len(list(filter(lambda g: not isinstance(g, SelectionWidget), self.global_parameter)))
+
         if set_id is None:
             for val, g in zip(parameter, self.global_parameter):
                 if isinstance(g, SelectionWidget):
@@ -271,13 +273,13 @@ class QFitParameterWidget(QtWidgets.QWidget, Ui_FormFit):
 
         else:
             new_param = self.data_values[set_id]
-            min_len = min(len(new_param), len(parameter))
+            min_len = min(param_len, len(new_param), len(new_param))
             for i in range(min_len):
                 new_param[i] = parameter[i]
 
             self.change_data(self.comboBox.currentIndex())
 
-        return len(self.global_parameter)
+        return param_len
 
 
 class ParameterSingleWidget(QtWidgets.QWidget):
diff --git a/src/gui_qt/io/filereaders.py b/src/gui_qt/io/filereaders.py
index 7ebed93..11d28c2 100755
--- a/src/gui_qt/io/filereaders.py
+++ b/src/gui_qt/io/filereaders.py
@@ -58,7 +58,7 @@ class QFileReader(QtCore.QObject):
             try:
                 # If QAsciiReader.skip = True it accepts automatically and returns None
                 r(f).exec()
-            except ImportError:
+            except AttributeError:
                 pass
 
         self.data_read.emit(self.data)
diff --git a/src/gui_qt/lib/pg_objects.py b/src/gui_qt/lib/pg_objects.py
index c8626e0..4ab0f30 100644
--- a/src/gui_qt/lib/pg_objects.py
+++ b/src/gui_qt/lib/pg_objects.py
@@ -380,6 +380,8 @@ class RegionItem(LinearRegionItem):
 
         self.logmode = False
         self.first = True
+        if not hasattr(self, '_bounds') and hasattr(self, '_boundingRectCache'):
+            self._bounds = self._boundingRectCache
 
     def setLogMode(self, xmode, _):
         if self.logmode == xmode:
diff --git a/src/resources/_ui/fitfuncwidget.ui b/src/resources/_ui/fitfuncwidget.ui
index 5c8bdcc..2d4be34 100644
--- a/src/resources/_ui/fitfuncwidget.ui
+++ b/src/resources/_ui/fitfuncwidget.ui
@@ -6,10 +6,16 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>292</width>
+    <width>308</width>
     <height>477</height>
    </rect>
   </property>
+  <property name="sizePolicy">
+   <sizepolicy hsizetype="MinimumExpanding" vsizetype="Preferred">
+    <horstretch>0</horstretch>
+    <verstretch>0</verstretch>
+   </sizepolicy>
+  </property>
   <property name="windowTitle">
    <string>Form</string>
   </property>
@@ -73,8 +79,8 @@
            <rect>
             <x>0</x>
             <y>0</y>
-            <width>284</width>
-            <height>442</height>
+            <width>304</width>
+            <height>444</height>
            </rect>
           </property>
          </widget>
@@ -88,7 +94,20 @@
       </attribute>
       <layout class="QVBoxLayout" name="verticalLayout_3">
        <item>
-        <widget class="QComboBox" name="comboBox"/>
+        <widget class="QComboBox" name="comboBox">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <property name="maximumSize">
+          <size>
+           <width>288</width>
+           <height>16777215</height>
+          </size>
+         </property>
+        </widget>
        </item>
        <item>
         <widget class="QScrollArea" name="scrollArea2">
@@ -109,8 +128,8 @@
            <rect>
             <x>0</x>
             <y>0</y>
-            <width>272</width>
-            <height>357</height>
+            <width>286</width>
+            <height>393</height>
            </rect>
           </property>
          </widget>