I share my "stack" experience about a table two-column wide. How to do it? Professor Google immeidately tells you you can use "table*" environment instead of "table" by adding just an asterisk "*". Easy.

  \begin{table*}[H]
  \centering
  \includegraphics[resolution=100]{tables/4_3_5_tab_compare_atag.png}
  \caption{Incidence by codon}
  \label{tab:4_3_5_compare_atag.png}
  See abbreviations on page \pageref{acronyms2}.
  \end{table*}

In my case, I just added it, and then somehow the table is gone and can not be found anywhere. It is simply gone. Remove "*" then the table came back. So it is obviously this asterisk, which is doing wrong.

Google did not help. I started to debug. The problem was [H]. "table*" environment does not support it, although "table" does. And that hides the table.

Hope it helps.

Acutally I had my code for my thesis. Now I am making an article with two columns. I never thought it hides the table, and I had no idea what was wrong. I spent much time, doing some package on and off and so on, for no luck. I at last made a MWC, minimal working code. Yes, MWC is the key to solve your problem fast. It seems a long shot but it is a short cut :)