Nobody will help you because you're a noobs which tried to update without reading errata file. In the errata file, it is clearly stated that you must disable all plugins before running the i-mscp installer... Your problem is fairly simple: You have a old plugin version that call a method which has been removed from i-MSCP core.
So what now? You must manually disable the plugins in the database and once done, give a new try. How? Search on our forum.
