only one ID if no link-multiple

application/Espo/Core/Record/Access/LinkCheck.php

@@ -148,7 +148,7 @@ class LinkCheck
                 continue;
             }
 
-            $this->processCheckLinkWithoutField($entityDefs, $name, $this->manyFieldTypeList);
+            $this->processCheckLinkWithoutField($entityDefs, $name, $this->manyFieldTypeList, $setIds);
 
             $names = $this->prepareNames($entity, $namesAttribute, $setIds);
 
@@ -172,8 +172,12 @@ class LinkCheck
      * @param string[] $fieldTypes
      * @throws Forbidden
      */
-    private function processCheckLinkWithoutField(EntityDefs $entityDefs, string $name, array $fieldTypes): void
-    {
+    private function processCheckLinkWithoutField(
+        EntityDefs $entityDefs,
+        string $name,
+        array $fieldTypes,
+        ?array $ids = null
+    ): void {
         $hasField =
             $entityDefs->hasField($name) &&
             in_array($entityDefs->getField($name)->getType(), $fieldTypes);
@@ -182,6 +186,10 @@ class LinkCheck
             return;
         }
 
+        if ($ids !== null && count($ids) > 1) {
+            throw new ForbiddenSilent("Cannot set multiple IDs for link '$name' as there's no link-multiple field");
+        }
+
         $forbiddenLinkList = $this->acl->getScopeForbiddenLinkList($entityDefs->getName(), AclTable::ACTION_EDIT);
 
         if (!in_array($name, $forbiddenLinkList)) {