Let's translate your error: allowed memory size of 134217728 bytes exhausted (tried to allocate 24848 bytes)
= allowed memory size of 128M exhausted (tried to allocate 0.023696899M ). You can use a converter from
bytes to mebibyte. Type bytes in mb in Google Serach and should show google converter (see attachment). From the dropdown menu choose bytes and mebibyte (M). Megabyte is MB.
Your error says that you exhausted the 128M memory limit you have. For that image you uploaded when you got that error you need other 0.023696899M. For that image 128M memory limit was not enough. For every image the error will tell you how much you still need.
You can insist to find a solution, but even the coppermine docs says that this error is about the memory limit. It can not be something else. Is nothing you can do.
You did not answer one of my questions: Do you have access to php.ini on your host? You have to edit php.ini. In phpinfo.php file find Loaded Configuration File that shows you where is php.ini in your file manager, but you should have PHP Setting in your Cpanel somewhere to find it easier. Ask the host if you can edit php.ini if you don't find it.
If your host restricts their users to edit php.ini then ask them to increase at 150M.
On my localhost (I installed php and server on PC) I have 150M.
On my host I have by default 200M. I never have to edit it, but I am allowed to edit it.
If you can't edit php.ini and the host won't do it for you, then the only way is this:
http://forum.coppermine-gallery.net/index.php/topic,76445.0.html but may not work on your host.
Another way is to make the image smaller with a photo editor, then use filezilla to overwrite the image on the server with the big image. Then you have to use coppermine Admin Tools to update thumbs (when you hove over the thumb will show the size of the image you uploaded with coppermine upload. need to update after overwrite to refresh image size ) .
If you have users then that's a problem. Only you can accesss the server with FileZilla.
I'm sorry but is no other way around it when you have this error. I'm sure of that.