diff --git a/go.sum b/go.sum
index 7104123cb..bebac81b3 100644
--- a/go.sum
+++ b/go.sum
@@ -57,14 +57,10 @@ github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XL
 github.com/chzyer/logex v1.2.0/go.mod h1:9+9sk7u7pGNWYMkh0hdiL++6OeibzJccyQU4p4MedaY=
 github.com/chzyer/readline v1.5.0/go.mod h1:x22KAscuvRqlLoK9CsoYsmxoXZMMFVyOl86cAH8qUic=
 github.com/chzyer/test v0.0.0-20210722231415-061457976a23/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
-github.com/clipperhouse/displaywidth v0.3.1 h1:k07iN9gD32177o1y4O1jQMzbLdCrsGJh+blirVYybsk=
-github.com/clipperhouse/displaywidth v0.3.1/go.mod h1:tgLJKKyaDOCadywag3agw4snxS5kYEuYR6Y9+qWDDYM=
 github.com/clipperhouse/displaywidth v0.6.0 h1:k32vueaksef9WIKCNcoqRNyKbyvkvkysNYnAWz2fN4s=
 github.com/clipperhouse/displaywidth v0.6.0/go.mod h1:R+kHuzaYWFkTm7xoMmK1lFydbci4X2CicfbGstSGg0o=
 github.com/clipperhouse/stringish v0.1.1 h1:+NSqMOr3GR6k1FdRhhnXrLfztGzuG+VuFDfatpWHKCs=
 github.com/clipperhouse/stringish v0.1.1/go.mod h1:v/WhFtE1q0ovMta2+m+UbpZ+2/HEXNWYXQgCt4hdOzA=
-github.com/clipperhouse/uax29/v2 v2.2.0 h1:ChwIKnQN3kcZteTXMgb1wztSgaU+ZemkgWdohwgs8tY=
-github.com/clipperhouse/uax29/v2 v2.2.0/go.mod h1:EFJ2TJMRUaplDxHKj1qAEhCtQPW2tJSwu5BF98AuoVM=
 github.com/clipperhouse/uax29/v2 v2.3.0 h1:SNdx9DVUqMoBuBoW3iLOj4FQv3dN5mDtuqwuhIGpJy4=
 github.com/clipperhouse/uax29/v2 v2.3.0/go.mod h1:Wn1g7MK6OoeDT0vL+Q0SQLDz/KpfsVRgg6W7ihQeh4g=
 github.com/cockroachdb/apd v1.1.0/go.mod h1:8Sl8LxpKi29FqWXR16WEFZRNSz3SoPzUzeMeY4+DwBQ=
@@ -364,12 +360,8 @@ github.com/olekukonko/cat v0.0.0-20250911104152-50322a0618f6 h1:zrbMGy9YXpIeTnGj
 github.com/olekukonko/cat v0.0.0-20250911104152-50322a0618f6/go.mod h1:rEKTHC9roVVicUIfZK7DYrdIoM0EOr8mK1Hj5s3JjH0=
 github.com/olekukonko/errors v1.1.0 h1:RNuGIh15QdDenh+hNvKrJkmxxjV4hcS50Db478Ou5sM=
 github.com/olekukonko/errors v1.1.0/go.mod h1:ppzxA5jBKcO1vIpCXQ9ZqgDh8iwODz6OXIGKU8r5m4Y=
-github.com/olekukonko/ll v0.1.2 h1:lkg/k/9mlsy0SxO5aC+WEpbdT5K83ddnNhAepz7TQc0=
-github.com/olekukonko/ll v0.1.2/go.mod h1:b52bVQRRPObe+yyBl0TxNfhesL0nedD4Cht0/zx55Ew=
 github.com/olekukonko/ll v0.1.3 h1:sV2jrhQGq5B3W0nENUISCR6azIPf7UBUpVq0x/y70Fg=
 github.com/olekukonko/ll v0.1.3/go.mod h1:b52bVQRRPObe+yyBl0TxNfhesL0nedD4Cht0/zx55Ew=
-github.com/olekukonko/tablewriter v1.1.1 h1:b3reP6GCfrHwmKkYwNRFh2rxidGHcT6cgxj/sHiDDx0=
-github.com/olekukonko/tablewriter v1.1.1/go.mod h1:De/bIcTF+gpBDB3Alv3fEsZA+9unTsSzAg/ZGADCtn4=
 github.com/olekukonko/tablewriter v1.1.2 h1:L2kI1Y5tZBct/O/TyZK1zIE9GlBj/TVs+AY5tZDCDSc=
 github.com/olekukonko/tablewriter v1.1.2/go.mod h1:z7SYPugVqGVavWoA2sGsFIoOVNmEHxUAAMrhXONtfkg=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
@@ -404,8 +396,6 @@ github.com/prometheus/common v0.66.1 h1:h5E0h5/Y8niHc5DlaLlWLArTQI7tMrsfQjHV+d9Z
 github.com/prometheus/common v0.66.1/go.mod h1:gcaUsgf3KfRSwHY4dIMXLPV0K/Wg1oZ8+SbZk/HH/dA=
 github.com/prometheus/procfs v0.17.0 h1:FuLQ+05u4ZI+SS/w9+BWEM2TXiHKsUQ9TADiRH7DuK0=
 github.com/prometheus/procfs v0.17.0/go.mod h1:oPQLaDAMRbA+u8H5Pbfq+dl3VDAvHxMUOVhe0wYB2zw=
-github.com/redis/go-redis/v9 v9.17.1 h1:7tl732FjYPRT9H9aNfyTwKg9iTETjWjGKEJ2t/5iWTs=
-github.com/redis/go-redis/v9 v9.17.1/go.mod h1:u410H11HMLoB+TP67dz8rL9s6QW2j76l0//kSOd3370=
 github.com/redis/go-redis/v9 v9.17.2 h1:P2EGsA4qVIM3Pp+aPocCJ7DguDHhqrXNhVcEp4ViluI=
 github.com/redis/go-redis/v9 v9.17.2/go.mod h1:u410H11HMLoB+TP67dz8rL9s6QW2j76l0//kSOd3370=
 github.com/remyoudompheng/bigfft v0.0.0-20200410134404-eec4a21b6bb0/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
diff --git a/pkg/models/project_duplicate.go b/pkg/models/project_duplicate.go
index 8d904f8b1..26985333a 100644
--- a/pkg/models/project_duplicate.go
+++ b/pkg/models/project_duplicate.go
@@ -325,7 +325,7 @@ func duplicateProjectBackground(s *xorm.Session, pd *ProjectDuplicate, doer web.
 
 	log.Debugf("Duplicated project background from project %d into %d", pd.ProjectID, pd.Project.ID)
 
-	return
+	return nil
 }
 
 func duplicateTasks(s *xorm.Session, doer web.Auth, ld *ProjectDuplicate) (newTaskIDs map[int64]int64, err error) {
diff --git a/pkg/models/project_duplicate_test.go b/pkg/models/project_duplicate_test.go
index 655784af3..a89342edb 100644
--- a/pkg/models/project_duplicate_test.go
+++ b/pkg/models/project_duplicate_test.go
@@ -28,18 +28,30 @@ import (
 )
 
 func TestProjectDuplicate(t *testing.T) {
+	t.Run("duplicate project", func(t *testing.T) {
+		testProjectDuplicate(t, 1, 1)
+	})
 
+	t.Run("duplicate project with uploaded background", func(t *testing.T) {
+		// Project 35 has a background_file_id of 1, which is NOT an Unsplash photo
+		// This tests the fix for issue #1745 where duplicating a project with an uploaded
+		// (non-Unsplash) background would fail with an internal server error
+		testProjectDuplicate(t, 35, 6)
+	})
+}
+
+func testProjectDuplicate(t *testing.T, projectID int64, userID int64) {
 	files.InitTestFileFixtures(t)
 	db.LoadAndAssertFixtures(t)
 	s := db.NewSession()
 	defer s.Close()
 
 	u := &user.User{
-		ID: 1,
+		ID: userID,
 	}
 
 	l := &ProjectDuplicate{
-		ProjectID: 1,
+		ProjectID: projectID,
 	}
 	can, err := l.CanCreate(s, u)
 	require.NoError(t, err)
@@ -118,6 +130,7 @@ func TestProjectDuplicate(t *testing.T) {
 	}
 
 	// Check that the kanban view in the duplicated project has a different default bucket than the original
+	// (only if the original kanban view has a default bucket configured)
 	var originalKanbanView *ProjectView
 	var duplicatedKanbanView *ProjectView
 
@@ -135,10 +148,7 @@ func TestProjectDuplicate(t *testing.T) {
 		}
 	}
 
-	require.NotNil(t, originalKanbanView, "Original project does not have a kanban view")
-	require.NotNil(t, duplicatedKanbanView, "Duplicated project does not have a kanban view")
-
-	if originalKanbanView != nil && duplicatedKanbanView != nil {
+	if originalKanbanView != nil && duplicatedKanbanView != nil && originalKanbanView.DefaultBucketID != 0 {
 		assert.NotEqual(t, originalKanbanView.DefaultBucketID, duplicatedKanbanView.DefaultBucketID)
 	}
 }