diff --git a/duchain/builders/declarationbuilder.cpp b/duchain/builders/declarationbuilder.cpp
--- a/duchain/builders/declarationbuilder.cpp
+++ b/duchain/builders/declarationbuilder.cpp
@@ -177,9 +177,11 @@
             setComment(m_lastConstComment);
         }
         DUChainWriteLocker lock;
-        Declaration* dec = openDeclaration<Declaration>(identifier.last(), editorFindRange(id, 0));
-        dec->setType<AbstractType>(type);
-        dec->setKind(Declaration::Instance);
+        auto dec = openDeclaration<Declaration>(identifier.last(), editorFindRange(id, 0));
+        if (dec) {
+          dec->setType<AbstractType>(type);
+          dec->setKind(Declaration::Instance);
+        }
         closeDeclaration();
     }
 }
diff --git a/duchain/builders/usebuilder.cpp b/duchain/builders/usebuilder.cpp
--- a/duchain/builders/usebuilder.cpp
+++ b/duchain/builders/usebuilder.cpp
@@ -43,11 +43,17 @@
     QualifiedIdentifier id(identifierForNode(node->name));
     if(node->type_resolve->fullName)
         id.push(identifierForNode(node->type_resolve->fullName));
-    DUContext* context;
-    {
-        DUChainReadLocker lock;
-        context = currentContext()->findContextIncluding(editorFindRange(node, 0));
+
+    DUChainReadLocker lock;
+    auto currentCtx = currentContext();
+    lock.unlock();
+    if (!currentCtx) {
+      qCInfo(DUCHAIN) << "Current ctx is null";
+      return;
     }
+    auto context = currentCtx->findContextIncluding(editorFindRange(node, 0));
+    if(!context) return;
+
     DeclarationPointer decl = getTypeDeclaration(id, context);
     if(decl)
     {
@@ -58,12 +64,14 @@
 
 void UseBuilder::visitPrimaryExpr(PrimaryExprAst* node)
 {
-    DUContext* context;
-    {
-        DUChainReadLocker lock;
-        //context = currentContext()->findContextAt(editorFindRange(node, 0).start);
-        context = currentContext()->findContextIncluding(editorFindRange(node, 0));
+    DUChainReadLocker lock;
+    auto currentCtx = currentContext();
+    lock.unlock();
+    if (!currentCtx) {
+      qCInfo(DUCHAIN) << "Current ctx is null";
+      return;
     }
+    auto context = currentCtx->findContextIncluding(editorFindRange(node, 0));
     if(!context) return;
     ExpressionVisitor visitor(m_session, context);
     visitor.visitPrimaryExpr(node);
@@ -171,11 +179,15 @@
     }
 
     QualifiedIdentifier id(identifierForNode(typeIdentifierNode));
-    DUContext* context;
-    {
-        DUChainReadLocker lock;
-        context = currentContext()->findContextIncluding(editorFindRange(typeIdentifierNode, 0));
+    DUChainReadLocker lock;
+    auto currentCtx = currentContext();
+    lock.unlock();
+    if (!currentCtx) {
+      qCInfo(DUCHAIN) << "Current ctx is null";
+      return;
     }
+    auto context = currentCtx->findContextIncluding(editorFindRange(typeIdentifierNode, 0));
+    if(!context) return;
     DeclarationPointer declaration = getTypeDeclaration(id, context);
     if(declaration)
     {
diff --git a/duchain/declarations/functiondeclaration.cpp b/duchain/declarations/functiondeclaration.cpp
--- a/duchain/declarations/functiondeclaration.cpp
+++ b/duchain/declarations/functiondeclaration.cpp
@@ -19,6 +19,8 @@
 #include "functiondeclaration.h"
 #include <language/duchain/duchainregister.h>
 
+#include "duchaindebug.h"
+
 using namespace KDevelop;
 
 namespace go {
@@ -70,7 +72,12 @@
 
 DUContext* GoFunctionDeclaration::returnArgsContext() const
 {
-    return d_func()->returnContext.context();
+  auto df = d_func();
+  if (!df->returnContext.isValid()) {
+    qCInfo(DUCHAIN) << "Context not valid";
+    return nullptr;
+  }
+  return df->returnContext.context();
 }
 
-}
\ No newline at end of file
+}