It appears you have had a similar issue before.
https://developers.oxwall.com/forum/topic/51581
This is why we ask you to disable all third party plugins.
Message:SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'id' cannot be null
File:/srv/disk1/1746522/www/colossus.fi/ow/ow_core/database.php
Line:723
Trace:
#0 /srv/disk1/1746522/www/colossus.fi/ow/ow_core/database.php(723): PDOStatement->execute()
#1 /srv/disk1/1746522/www/colossus.fi/ow/ow_core/database.php(476): OW_Database->execute('INSERT INTO `tu...', Array)
#2 /srv/disk1/1746522/www/colossus.fi/ow/ow_core/database.php(512): OW_Database->insert('INSERT INTO `tu...', Array)
#3 /srv/disk1/1746522/www/colossus.fi/ow/ow_core/base_dao.php(216): OW_Database->insertObject('tucg_blogs_post', Object(Post))
#4 /srv/disk1/1746522/www/colossus.fi/ow/ow_plugins/blogs/bol/service/post_service.php(97): OW_BaseDao->save(Object(Post))
#5 /srv/disk1/1746522/www/colossus.fi/ow/ow_plugins/blogs/controllers/save.php(314): PostService->save(Object(Post))
#6 /srv/disk1/1746522/www/colossus.fi/ow/ow_plugins/blogs/controllers/save.php(118): SaveForm->process(Object(BLOGS_CTRL_Save))
#7 [internal function]: BLOGS_CTRL_Save->index(Array)
#8 /srv/disk1/1746522/www/colossus.fi/ow/ow_core/request_handler.php(250): ReflectionMethod->invokeArgs(Object(BLOGS_CTRL_Save), Array)
#9 /srv/disk1/1746522/www/colossus.fi/ow/ow_core/request_handler.php(226): OW_RequestHandler->processControllerAction(Object(ReflectionMethod), Object(BLOGS_CTRL_Save))
#10 /srv/disk1/1746522/www/colossus.fi/ow/ow_core/application.php(346): OW_RequestHandler->dispatch()
#11 /srv/disk1/1746522/www/colossus.fi/ow/index.php(76): OW_Application->handleRequest()
#12 {main}
Type:PDOException
I put the site into maintenance mode.
"Before uninstalling blogs plugin we have to remove all existing user content. This may take awhile. That is why we will put the site to "maintenance mode" and activate it back upon completing the uninstall."
Does it delete blogs from database or images from server?
In which order should I now continue, there's following things to do:
1. old blog images from backup
2. restore mysql tucg_blogs_categories, tucg_blogs_featured, tucg_blogs_post to new database
3. install advanced blogs plugin
4. customize advanced blogs settings/language
Is this the right order?
The blogs plugin works just fine, if you install that advanced blog plugin and you have issues again, please post your support request on the plugin page not here as it has nothing to do with the blog plugin.