diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a5cefe05..49391955 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -175,7 +175,6 @@ jobs:
         if: matrix.ostype == 'mac'
         with:
           python-version: '3.11'
-          cache: 'pip'
 
       - name: Install Conan
         id: conan
@@ -216,16 +215,14 @@ jobs:
           linux-local-args: '["--toolkit"]'
 
       - name: Install CUDA Toolkit
-        uses: Jimver/cuda-toolkit@v0.2.14
+        uses: Jimver/cuda-toolkit@v0.2.16
         id: cuda-toolkit-win
         if: matrix.ostype == 'windows' && matrix.cuda == true
         with:
-          cuda: '12.1.0'
+          # Need CUDA >= 12.4 to support recent VS2022 (17.10 and later, MSVC 19.40)
+          cuda: '12.4.1'
           method: 'network'
           sub-packages: '["nvcc", "cudart"]'
-          # workaround for cuda-toolkit action bug https://github.com/Jimver/cuda-toolkit/issues/315
-          use-github-cache: false
-          use-local-cache: false
 
       # - name: Install system dependencies (CentOS)
       #   run: |
diff --git a/scripts/build-cmake.sh b/scripts/build-cmake.sh
index 8ae476d2..2ac1f58b 100755
--- a/scripts/build-cmake.sh
+++ b/scripts/build-cmake.sh
@@ -78,6 +78,39 @@ else
     exit 1
 fi
 
+if [[ ! -f ./conanfile.py ]]; then
+    echo "***"
+    echo "*** ERROR: please run this script from the top level dir, where conanfile.py and readme.md are."
+    echo "***"
+    exit 1
+fi
+
+
+# Ensure standard plugin install folder exists and is writable, unless user is
+# building with a custom plugin install dir.
+if [[ ! $ARGS =~ .*PLUGIN_INSTALLDIR.* ]] ; then
+    if [[ -n $COMMONPROGRAMFILES && -d $COMMONPROGRAMFILES ]]; then
+        INSTALLDIR="$COMMONPROGRAMFILES/OFX/Plugins"
+    elif [[ $(uname) = Darwin ]]; then
+        INSTALLDIR="/Library/OFX/Plugins"
+    else
+        INSTALLDIR="/usr/OFX/Plugins"
+    fi
+    # Try to create the plugin dir; this may fail due to permissions.
+    # We need it to exist and to be writable.
+    mkdir -p "$INSTALLDIR"
+    if [[ $? -ne 0 || ! -w $INSTALLDIR ]]; then
+        echo "***"
+        echo "*** ERROR: This script will install the built example plugins in $INSTALLDIR,"
+        echo "*** but that dir does not exist or isn't writable."
+        echo "*** Please run: sudo mkdir -p $INSTALLDIR && sudo chmod ugo+w $INSTALLDIR"
+        echo "*** or run this script with -DPLUGIN_INSTALL_DIR=<some dir> to install elsewhere."
+        echo "***"
+        exit 1
+    fi
+fi
+
+
 # Install dependencies, set up build dir, and generate build files.
 echo === Running conan to install dependencies
 [[ $USE_OPENCL ]] && conan_opts="$conan_opts -o use_opencl=True"
@@ -99,4 +132,4 @@ echo "  Plugin support lib and examples are in ${CMAKE_BUILD_DIR}/Support/{Libra
 echo "  Host lib is in ${CMAKE_BUILD_DIR}/HostSupport/${BUILDTYPE}"
 echo "=== To (re)install the sample plugins to your OFX plugins folder, become root if necessary, and then do:"
 echo "  cmake --install ${CMAKE_BUILD_DIR}"
-echo "  (pass -DINSTALLDIR=<path> to this script or cmake to install elsewhere than the standard OFX folder)"
+echo "  (pass -DPLUGIN_INSTALLDIR=<path> to this script or cmake to install elsewhere than the standard OFX folder)"