This usually indicates some form of syntax error in the file. And then you get a long error message trying to pinpoint the exact location of the error and finally you get a message that says "Compilation failed in require at /path/to/coranto.cgi line 75".

This is a problem possibly related to a bug in Coranto version 1.23 regarding If/Else If-statments, so if you have upgraded your copy of Coranto to this version you can read about the problem and solution in this thread:
http://coranto.gweilo.org/forum/viewtopic.php?t=6401

If you haven´t upgraded Coranto there might be a problem in one of your styles. Try and open the file crcfg.dat and look at the line which is pointed out by the error message. One or many lines above that line you should recognize the name of one of your styles, now log in to Coranto and resave that style and if you don´t get an error message, do a full rebuild. If you do get an error message when saving the style post that style in the forum, stating that you have read this document and explain what measures you have taken thus far to pinpoint the problem.