Not Enough Memory

I tend to say it's a memory leak. Is the server you're trying to join using mysqloo?

Gmod is x86, it can't allocate more than ~4Gb of ram

To extend what I wrote earlier:

I know this issue fairly well on a server. In my case it was a memory leak caused by the old version of MySQLoo where the MySQL Garbage Collection wasn't called properly. It was fixed by changing to (what back then was) the newer tmysql4 (now the new version of MySQLoo is the new standard). Does this issue happen on the client or on the server? If it's on the client, is it only on a specific server or in general on every server? If it happens on a specific server, do other people encounter the same issue? And what kind of server would that be (gamemode/hardware)?

If your FPS start decreasing right before the crash, try this to find the cause

If its on your client, try factory resetting Gmod (there's a .bat in the gmod folder for that), also verify the game's integrity via Steam.

If it's on your server, try removing every addon and adding them back 1 by 1 and restart the server after you add one and check whether or not it's crashing. Using this method you can find the cause of the memory leak.

Using the client command "Net_Graph 3" (at least I believe it was 3 (correct me if otherwise)) you can also find out what may drain performance. If one category is extremely high you may be able to trace down what type of addon could potentially cause problems. As an example: If you see that Entities require a lot of performance, you should check which entities are currently present on your map, remove one by one and check the net graph whether it decreases or not. If you find an entity that rapidly decreases the entity net graph upon being removed, you know which addon drains that much performance. If it's a fairly simple or unpopular addon you might want to remove it because it could have a high potential of having badly written code which could cause the leak.

There could be hundreds of causes for this problem. If you want help: Answer all the questions I asked above and give me as much detail as possible, so I can help you.

@ momox thanks for the help and I appricaite that a lot I know whats wrong now and I solved it . but whenever I click on a entity its says failed to lock vertex and then crashes

Oof I have no clue about entities tho... Maybe one of the model experts here could help?

My community had a huge issue with this error. For us it turned out to be some sloppy code I written that sent a massive table to the user on initial spawn. I discovered the issue because the more you play the bigger this table got, so my more active members were the main ones with the issues. I don't know how Lua savvy you are but it might be worth looking in that direction a little if you end up still having the issue

and whenever to set my settings to low game crashes . dude gmod is bitching even tho I get high fps on high

Point being it's something on your server - we're not going to be able to solve it for you until you do some homework and figure out what it may be.

Shouldn't this thread be in off topic? Not sure if this is actually Gmodstore related.