I am recieving these errors and do not know how to fix them:

6 Database Problems Found 6
Other Information

Database schema version (None) does not match CMS version (3.0.0).
Database update version (3.1.5) does not match CMS version (3.0.0).
Table 'r1gfn_associations' does not have column 'id' with type 'INT(11)'. (From file 3.0.3.sql.)
Table 'r1gfn_contentitem_tag_map' does not exist. (From file 3.1.0.sql.)
Table 'r1gfn_tags' does not exist. (From file 3.1.0.sql.)
Table 'r1gfn_ucm_content' does not exist. (From file 3.1.0.sql.)

Database schema version (in #__schemas): None.
Update version (in #__extensions): 3.1.5.
Database driver: mysql.
66 database changes were checked successfully.
127 database changes did not alter table structure and were skipped.

Hi, only this informations are not enough for me, this is db error, have you tried to import a database? I thing you can found solution on joomla forum.