diff --git a/build.php b/build.php
index 10d5505..39115f9 100644
--- a/build.php
+++ b/build.php
@@ -39,8 +39,9 @@ if(!is_dir($builddir)){
     }
 }
 
-if(is_file($zipfile)){
-    unlink($zipfile);
+if(file_exists($zipfile)){
+    print("Zip file '{$zipfile}' already exists. Exiting...\n");
+    exit(1);
 }
 
 $cwd = getcwd();
diff --git a/view-plan.php b/view-plan.php
index ae8c283..6f34042 100644
--- a/view-plan.php
+++ b/view-plan.php
@@ -1,6 +1,8 @@
 <?php
 require_once("../../config.php");
 
+use \local_treestudyplan\courseservice;
+
 require_once($CFG->libdir.'/weblib.php');
 
 $systemcontext = context_system::instance();
@@ -29,8 +31,19 @@ elseif($contextid > 0)
 }
 else
 {
-	$categoryid = 0;
-	$studyplancontext = $systemcontext;
+	// If no context is selected, find the first available one
+	$available_contexts = courseservice::list_used_categories("view");
+	$contextid=1; // fallback to system context
+	foreach($available_contexts as $ctx){
+		if($ctx["studyplancount"] > 0){
+			$contextid = $ctx["context_id"];
+			break;
+		}
+	}
+	// reload page with selected category
+	$url = new \moodle_url('/local/treestudyplan/view-plan.php',["contextid" => $contextid]);
+	header('Location: '.$url->out(false), true, 302);
+	exit;
 }
 
 require_capability('local/treestudyplan:viewuserreports',$studyplancontext);
@@ -72,7 +85,6 @@ print $OUTPUT->header();
 					:active="ctx.context_id == contextid" :class="(ctx.studyplancount > 0)?'font-weight-bold':''"
 				><span v-for="(p,i) in ctx.category.path"><span v-if="i>0"> / </span>{{ p }}</span> <span>({{ ctx.studyplancount }})</b-form-select-option>
 			</b-form-select>
-
 		</div>
 		<h3 v-else><?php print $contextname; ?></h3>
 		<div class="m-buttonbar" style="margin-bottom: 1em;">