diff --git a/config.nims b/config.nims
index bd743434..b6c94124 100644
--- a/config.nims
+++ b/config.nims
@@ -15,20 +15,35 @@ switch("d", "allowConsoleLogger")
 
 switch("d", "wasm3HasWasi")
 switch("d", "wasm3VerboseErrorMessages")
+
+# switches for debugging
 # switch("d", "wasm3EnableStrace2")
 # switch("d", "wasm3RecordBacktraces")
-
 # switch("d", "wasm3LogModule")
 # switch("d", "wasm3LogCompile")
 # switch("d", "wasm3LogParse")
 # switch("d", "wasm3LogRuntime")
 # switch("d", "uiNodeDebugData")
+# switch("d", "futureLogging")
+# switch("d", "nimBurnFree")
+# switch("d", "nimArcIds")
+# switch("d", "traceArc")
+# switch("d", "nimTypeNames")
+
+# checks
+# --objChecks:off
+# --fieldChecks:off
+# --rangeChecks:off
+# --boundChecks:off
+# --overflowChecks:off
+# --floatChecks:off
+# --nanChecks:off
+# --infChecks:off
 
 # switch("cc", "vcc")
 # switch("nimcache", "D:\\nc")
 
-let mode = 0
-case mode
+case 0
 of 0:
   switch("d", "release")
 of 1:
@@ -39,11 +54,11 @@ of 2:
   switch("cc", "vcc")
   switch("d", "debug")
   switch("debuginfo", "on")
-  switch("nimcache", "nimcache")
 of 3:
   switch("d", "release")
   switch("debuginfo", "on")
-  switch("cc", "vcc")
+  switch("stackTrace", "on")
+  switch("lineTrace", "on")
   switch("nimcache", "D:\\nc")
 else:
   discard
diff --git a/src/absytree_dynlib.nim b/src/absytree_dynlib.nim
index 09040014..d3de8ee0 100644
--- a/src/absytree_dynlib.nim
+++ b/src/absytree_dynlib.nim
@@ -14,7 +14,7 @@ else:
   static:
     echo "Compiling for unknown"
 
-import std/[parseopt, options, macros]
+import std/[parseopt, options, macros, tables]
 import misc/[custom_logger]
 import compilation_config, scripting_api, app_options
 
@@ -85,10 +85,12 @@ proc shutdown() =
   if gApp.isNotNil:
     log lvlInfo, "Shutting down editor"
     gApp.shutdown()
+    gApp = nil
 
   if rend.isNotNil:
     log lvlInfo, "Shutting down platform"
     rend.deinit()
+    rend = nil
 
 proc NimMain() {.cdecl, importc.}
 
@@ -108,6 +110,18 @@ proc absytree_poll(timeoutMs: int32) {.exportc, dynlib, cdecl.} =
 proc absytree_shutdown() {.exportc, dynlib, cdecl.} =
   echo "Shutting down Absytree..."
   shutdown()
+
+  when isFutureLoggingEnabled:
+    while hasPendingOperations():
+      debugf"Futures in progress:"
+      debugf"----------------------------"
+      for (info, x) in getFuturesInProgress().pairs:
+        debugf"{info.fromProc}: {info.stackTrace}"
+      debugf"----------------------------"
+      drain(100)
+
+  else:
+    drain(10000)
   GC_FullCollect()
 
 proc absytree_input_keys*(self: ptr AppObject, input: cstring) {.exportc, dynlib, cdecl.} =
diff --git a/src/ast/lang/cell_language.nim b/src/ast/lang/cell_language.nim
index a0b3fe57..46fcf443 100644
--- a/src/ast/lang/cell_language.nim
+++ b/src/ast/lang/cell_language.nim
@@ -217,7 +217,7 @@ proc createCellLanguage*(): Future[Language] {.async.} =
     log lvlError, "createCellLanguage: Failed to load cell builder model"
     return Language nil
 
-  var language = createLanguageFromModel(model).await
+  var language = createLanguageFromModel(model, createBuilder = false).await
   language.name = "Cells"
   language.scopeComputers = scopeComputers
   return language
diff --git a/src/ast/lang/lang_builder.nim b/src/ast/lang/lang_builder.nim
index 0bd8f8c0..460bc7a1 100644
--- a/src/ast/lang/lang_builder.nim
+++ b/src/ast/lang/lang_builder.nim
@@ -462,12 +462,12 @@ proc updateLanguageFromModel*(language: Language, model: Model, updateBuilder: b
 
   return true
 
-proc createLanguageFromModel*(model: Model, ctx = ModelComputationContextBase.none): Future[Language] {.async.} =
+proc createLanguageFromModel*(model: Model, ctx = ModelComputationContextBase.none, createBuilder: bool = true): Future[Language] {.async.} =
   log lvlInfo, fmt"createLanguageFromModel {model.path} ({model.id})"
 
   let name = model.path.splitFile.name
   let language = newLanguage(model.id.LanguageId, name)
-  if not language.updateLanguageFromModel(model, ctx = ctx).await:
+  if not language.updateLanguageFromModel(model, ctx = ctx, updateBuilder = createBuilder).await:
     return Language nil
   return language
 
diff --git a/src/ast/model.nim b/src/ast/model.nim
index 5756adc3..48acd704 100644
--- a/src/ast/model.nim
+++ b/src/ast/model.nim
@@ -60,7 +60,7 @@ type
     role*: string
     class*: ClassId
 
-  NodeClass* = ref object
+  NodeClass* {.acyclic.} = ref object
     id {.getter.}: ClassId
     name {.getter.}: string
     alias {.getter.}: string
@@ -78,13 +78,13 @@ type
     canBeRoot {.getter.}: bool
     registryIndex: int32 # Index in the global node registry (0 if not registered)
 
-  AstNode* = ref object
+  AstNode* {.acyclic.} = ref object
     id*: NodeId
     class*: ClassId
 
     registryIndex: int32 # Index in the global node registry (0 if not registered)
     model*: Model # gets set when inserted into a parent node which is in a model, or when inserted into a model
-    parent*: AstNode # gets set when inserted into a parent node
+    parent* {.cursor.}: AstNode # gets set when inserted into a parent node
     role*: RoleId # gets set when inserted into a parent node
 
     properties*: seq[tuple[role: RoleId, value: PropertyValue]]
@@ -111,7 +111,7 @@ type
 
   ModelComputationContextBase* = ref object of RootObj
 
-  Language* = ref object
+  Language* {.acyclic.} = ref object
     name* : string
     id {.getter.}: LanguageId
     version {.getter.}: int
diff --git a/src/ast/project.nim b/src/ast/project.nim
index 01cfc467..1d3f515b 100644
--- a/src/ast/project.nim
+++ b/src/ast/project.nim
@@ -52,7 +52,10 @@ proc loadModelAsync*(project: Project, path: string): Future[Option[Model]] {.as
 
   let ws = getProjectWorkspace().await
   let jsonText = ws.loadFile(path).await
-  let json = jsonText.parseJson
+
+  let json = jsonText.parseJson.catch:
+    log lvlError, &"project.loadModelAsync: Failed to parse json: {getCurrentExceptionMsg()}\n{getCurrentException().getStackTrace()}"
+    return Model.none
 
   var model = newModel()
   if not model.loadFromJsonAsync(project, ws, path, json, resolveLanguage, resolveModel).await:
diff --git a/src/text/language/lsp_client.nim b/src/text/language/lsp_client.nim
index 03012358..e50518b7 100644
--- a/src/text/language/lsp_client.nim
+++ b/src/text/language/lsp_client.nim
@@ -110,7 +110,7 @@ proc parseResponse(client: LSPClient): Future[JsonNode] {.async.} =
 
   if client.connection.isNil:
     log(lvlError, "[parseResponse] Connection is nil")
-    return nil
+    return JsonNode(nil)
 
   var success = true
   var lines = @[line]