Everytime i play the game for about 20 minutes or so, gta will freeze then say gta 4 has stopped working or is not responding? Is there a way to fix it?

this has been answered many time 

 

Problem: Third-party modifications can hamper your game experience and cause issues with the GTA engine. This is almost always not caused by LCPDFR itself.

Solution: Remove car modifications with a high polygon (poly) count. These are not handled gracefully by the game engine and these modifications can sometimes have 10x the polygons of original unmodded vehicles! Other modifications cause crashing, most usually the ELS modification, which works by constantly changing a vehicle's parts!
Most people assume LCPDFR is causing their issues because they install car mods, ELS and then LCPDFR last.

Credit to Jay. 

Everytime i play the game for about 20 minutes or so, gta will freeze then say gta 4 has stopped working or is not responding? Is there a way to fix it?

 

Yea, this topic has been answered at least 5x a day, everyday.  What Code3 said above and also Braveheart 2.2 (if you have it installed) will crash the game more times than not, at least for many.  Use 2.1 and that may solve your issue of crashing.

 

 

Good day,

 

DrDetroit