The Revolution of 1905 was caused by several factors, including (the emancipation of the serfs, Bloody Sunday, Nationalism), (poor working conditions, ongoing existence of enslaved of serfs, censorship) and (Russia's loss to France, Russia's loss to Japan, Russia's loss to the Ottomen Empire).

Bloody Sunday, poor working conditions, and Russia's loss to Japan.

I'm not 100% sure on poor working conditions though, sorry.

The Russian Revolution of 1905 was a series of mass social and political unrest that occupied a wide area of the Empire. The revolution included peasent unrest, labor strikes and military riots. One of the causes that led to the Revolution was long-term economic and political dissatisfaction. This is primarily related to poor working conditions, which were present due to unrealized economic reforms, due to the lack of interest of Emperor Nicholas to deal with them. One of the long-term causes that led to the Revolution was loss to Japan, and it was not the only defeat of Russia in those years. The people were already tired of the wars, especially due to frequent defeats, which further exacerbated the already bad economic situation. The short-term cause, which was literally the trigger for the Revolution, was Bloody Sunday, after which the Emperor lost control over many parts of Russia.

Russian serfdom was abolished long before the Revolution, or more precisely in 1861, in the reform of emancipation, while practically in some parts of Russia it was conducted a decade or two later. Of course within these reasons there are also unsolved economic problems of serfs as an integral part of poor working conditions.