diff --git a/plugin/sensor/touch_grid.cc b/plugin/sensor/touch_grid.cc
index 9906d149..27bf08b0 100644
--- a/plugin/sensor/touch_grid.cc
+++ b/plugin/sensor/touch_grid.cc
@@ -177,52 +177,52 @@ TouchGrid* TouchGrid::Create(const mjModel* m, mjData* d,
     int nchannel = strtod(mj_getPluginConfig(m, instance, "nchannel"), nullptr);
     if (!nchannel) nchannel = 1;
     if (nchannel < 1 || nchannel > 6) {
-      mju_warning("nchannel must be between 1 and 6");
+      mju_error("nchannel must be between 1 and 6");
       return nullptr;
     }
 
     // size
     std::vector<int> size;
-    std::vector<mjtNum> fov;
-    ReadVector(
-        size, std::string(mj_getPluginConfig(m, instance, "size")).c_str());
-    ReadVector(
-        fov, std::string(mj_getPluginConfig(m, instance, "fov")).c_str());
-    if (size[0] < 0 || size[1] < 0) {
-      mju_warning("Horizontal and vertical resolutions must be positive");
+    std::string size_str = std::string(mj_getPluginConfig(m, instance, "size"));
+    ReadVector(size, size_str.c_str());
+    if (size.size()!= 2) {
+      mju_error("Both horizontal and vertical resolutions must be specified");
       return nullptr;
     }
-    if (size.size()!= 2) {
-      mju_warning("Both horizontal and vertical resolutions must be specified");
+    if (size[0] <= 0 || size[1] <= 0) {
+      mju_error("Horizontal and vertical resolutions must be positive");
       return nullptr;
     }
 
     // field of view
+    std::vector<mjtNum> fov;
+    std::string fov_str = std::string(mj_getPluginConfig(m, instance, "fov"));
+    ReadVector(fov, fov_str.c_str());
+    if (fov.size()!= 2) {
+      mju_error(
+          "Both horizontal and vertical fields of view must be specified");
+      return nullptr;
+    }
     if (fov[0] <= 0 || fov[0] > 180) {
-      mju_warning("`fov[0]` must be a float between (0, 180] degrees");
+      mju_error("`fov[0]` must be a float between (0, 180] degrees");
       return nullptr;
     }
     if (fov[1] <= 0 || fov[1] > 90) {
-      mju_warning("`fov[1]` must be a float between (0, 90] degrees");
-      return nullptr;
-    }
-    if (fov.size()!= 2) {
-      mju_warning(
-          "Both horizontal and vertical fields of view must be specified");
+      mju_error("`fov[1]` must be a float between (0, 90] degrees");
       return nullptr;
     }
 
     // gamma
     mjtNum gamma = strtod(mj_getPluginConfig(m, instance, "gamma"), nullptr);
     if (gamma < 0 || gamma > 1) {
-      mju_warning("`gamma` must be a nonnegative float between [0, 1]");
+      mju_error("`gamma` must be a nonnegative float between [0, 1]");
       return nullptr;
     }
 
     return new TouchGrid(m, d, instance, nchannel, size.data(), fov.data(),
                          gamma);
   } else {
-    mju_warning("Invalid or missing parameters in touch_grid sensor plugin");
+    mju_error("Invalid or missing parameters in touch_grid sensor plugin");
     return nullptr;
   }
 }
@@ -489,7 +489,7 @@ void TouchGrid::RegisterPlugin() {
   plugin.name = "mujoco.sensor.touch_grid";
   plugin.capabilityflags |= mjPLUGIN_SENSOR;
 
-  // Parameterized by 5 attributes.
+  // Parameterized by 4 attributes.
   const char* attributes[] = {"nchannel", "size", "fov", "gamma"};
   plugin.nattribute = sizeof(attributes) / sizeof(attributes[0]);
   plugin.attributes = attributes;
@@ -502,8 +502,8 @@ void TouchGrid::RegisterPlugin() {
     int nchannel = strtod(mj_getPluginConfig(m, instance, "nchannel"), nullptr);
     if (!nchannel) nchannel = 1;
     std::vector<int> size;
-    ReadVector(
-        size, std::string(mj_getPluginConfig(m, instance, "size")).c_str());
+    std::string size_str = std::string(mj_getPluginConfig(m, instance, "size"));
+    ReadVector(size, size_str.c_str());
     return nchannel * size[0] * size[1];
   };