If after upgrading to 7.0, you are not able to open Markdown file and if your seahub.log containing some database error, it is caused by you forgot to migrate file comment when you upgrade to 6.3 version.
You can delete the table base_filecomment and recreate the table.
CREATE TABLE `base_filecomment` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`author` varchar(255) NOT NULL,
`comment` longtext NOT NULL,
`created_at` datetime NOT NULL,
`updated_at` datetime NOT NULL,
`uuid_id` char(32) NOT NULL,
`detail` longtext NOT NULL,
`resolved` tinyint(1) NOT NULL,
PRIMARY KEY (`id`),
KEY `base_filecomment_uuid_id_4f9a2ca2_fk_tags_fileuuidmap_uuid` (`uuid_id`),
KEY `base_filecomment_author_8a4d7e91` (`author`),
KEY `base_filecomment_resolved_e0717eca` (`resolved`),
CONSTRAINT `base_filecomment_uuid_id_4f9a2ca2_fk_tags_fileuuidmap_uuid` FOREIGN KEY (`uuid_id`) REFERENCES `tags_fileuuidmap` (`uuid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
If you are using SQLite, the statement is
CREATE TABLE "base_filecomment" (
"id" integer NOT NULL PRIMARY KEY AUTOINCREMENT,
"author" varchar(255) NOT NULL,
"comment" text NOT NULL,
"created_at" datetime NOT NULL,
"updated_at" datetime NOT NULL,
"uuid_id" char(32) NOT NULL REFERENCES "tags_fileuuidmap" ("uuid"),
"detail" text NOT NULL,
"resolved" bool NOT NULL);