It is possible to get this error:
Failed to get a recordset: postgres8 error: [-5: ERROR: duplicate key value violates unique constraint "blocinst_vierowcolord_uk" DETAIL: Key (view, "row", "column", "order")=(16, 1, 1, 1) already exists.] in EXECUTE("INSERT INTO "block_instance" ("id", "blocktype", "title", "configdata", "view", "column", "order", "row") VALUES (?, ?, ?, ?, ?, ?, ?, ?)")Command was: INSERT INTO "block_instance" ("id", "blocktype", "title", "configdata", "view", "column", "order", "row") VALUES (?, ?, ?, ?, ?, ?, ?, ?) and values was (id:8261,blocktype:textbox,title:Note,configdata:a:0:{},view:16,column:1,order:1,row:1)
To reproduce:
1. Create a new page
2. Click on the Note block
3. Do not click on Add nor on Cancel, but press ESC key (because you just realised that you have selected the wrong text block)
4. Click on the Text block
5. Click on the Add button
The problem here is the using of 'ESC' key is not cleaning up info about old block, so is trying to save the old and new block with same block position
In MySQL it behaves slightly differently and tries to display both blocks causing the config form to be confused