fix #238

src/documents/migrations/1010_auto_20210101_2159.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.1.4 on 2021-01-01 21:59
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('documents', '1009_auto_20201216_2005'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='savedviewfilterrule',
+            name='value',
+            field=models.CharField(blank=True, max_length=128, null=True),
+        ),
+    ]

src/documents/models.py

@@ -351,7 +351,10 @@ class SavedViewFilterRule(models.Model):
 
     rule_type = models.PositiveIntegerField(choices=RULE_TYPES)
 
-    value = models.CharField(max_length=128)
+    value = models.CharField(
+        max_length=128,
+        blank=True,
+        null=True)
 
 
 # TODO: why is this in the models file?