Android devices have limited memory to handle compressed images files. If you get an out of memory error while viewing a file, here is a list of workarounds that might solve the problem and also improve the performance. In order:
If the file is CBR/RAR, extract its contents and package it as a CBZ/ZIP file with no compression. You can use ComicRack to batch convert CBR files to CBZ.
If the file is CBZ/ZIP, please verify that it's not a improperly named CBR/RAR file.
If you have confirmed that the file is a CBZ/ZIP file, extract its contents into a folder in the SD card and open the folder from Droid Comic Viewer using a long tap on the SD Browser.
Turn on Settings > Support > Low memory mode (available from version 1.3.10 onwards).
Reduce image resolution using Settings > Advanced > Max image width and Settings > Advanced > Max image height.
If it still fails after trying all of the above, please report a bug by just sending us the image file that causes the out of memory error.