# Maximum number of clients reachedERROR: In /home/aarju/VTK-7.1.1/Rendering/OpenGL2/vtkXOpenGLRenderWindow.cxx, line 1497 vtkXOpenGLRenderWindow (0x555dac8b7280): bad X server connection. DISPLAY=:0. Aborting.
**URL:** https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977
**Category:** Support
**Created:** [July 20, 2022, 8:52am UTC](https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977 "2022-07-20T08:52:16Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@guptaaarju](https://discourse.vtk.org/u/guptaaarju)
#### Post date: [July 20, 2022, 8:52am UTC](https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977/1 "2022-07-20T08:52:16Z")
Hi, I’m using VTK with QT.
After running 215 frames of point cloud data, My program is crashing and getting this error.
Maximum number of clients reachedERROR: In /home/aarju/VTK-7.1.1/Rendering/OpenGL2/vtkXOpenGLRenderWindow.cxx, line 1497
vtkXOpenGLRenderWindow (0x555dac8b7280): bad X server connection. DISPLAY=:0. Aborting.
If you know please leave the comment, Its very urgent.
---
### Author:  [@sankhesh](https://discourse.vtk.org/u/sankhesh)
#### Post date: [July 21, 2022, 3:59am UTC](https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977/2 "2022-07-21T03:59:41Z")
This looks more like a graphics driver issue to me. Did you try updating your driver and restarting the machine? If so, more specifics like code snippets, screenshots, etc. would help understand your use case.
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### Author:  [@guptaaarju](https://discourse.vtk.org/u/guptaaarju)
#### Post date: [July 21, 2022, 4:39am UTC](https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977/3 "2022-07-21T04:39:00Z")
Simply I am using it my local machine ubuntu 20.04 and visualise the code.
Code successfully run till 200 frames then crash it
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### Author:  [@sankhesh](https://discourse.vtk.org/u/sankhesh)
#### Post date: [July 21, 2022, 12:14pm UTC](https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977/4 "2022-07-21T12:14:00Z")
@guptaaarju It is also possible that your program is leaking memory and running out of GPU memory. If you need a more insightful response, you’d have to provide more details.
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### Author:  [@guptaaarju](https://discourse.vtk.org/u/guptaaarju)
#### Post date: [July 22, 2022, 3:15am UTC](https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977/5 "2022-07-22T03:15:02Z")
#include \
typedef pcl::PointXYZI PointT;
typedef pcl::PointCloud PointCloudT;
PointCloudT::Ptr input\_cloud;
pcl::visualization::PCLVisualizer::Ptr viewer\_3D;
The code is:
/_Reading LIDAR DATA( bin file format) functionality_/
void MainWindow::ReadInputFile(const std::string& CSV\_File)
{
```
PointT point;
std::vectorrow;
std::vectorrows;
std::string line, word;
/*Reset the Point Cloud container value*/
input_cloud.reset (new PointCloudT);
```
// viewer\_3D-\>removeAllPointClouds ();
// viewer\_3D-\>removeAllShapes();
// viewer\_3D-\>removeCoordinateSystem();
// viewer\_3D-\>close();
viewer\_3D.reset (new pcl::visualization::PCLVisualizer (“viewer\_3D”, false));
```
/*Reading Input file*/
fstream file (CSV_File.c_str(), ios::in);
getline(file,line);//For Heading Removing
while((getline(file, line)))//Row by Row interpreation
{
int count=0;
std::stringstream str(line);
while(getline(str, word, ','))
{
if(count<=2||count==6)
{
float value =stof(word);
row.push_back(value);
if(count==6)
{
break;
}
}
count++;
}
point.x=row[0];
point.y=row[1];
point.z=row[2];
point.intensity=row[3];
input_cloud->push_back(point);
row.clear();
}
/*Displaying Lidar Point on Display Window*/
ui->PCD_Viewer->SetRenderWindow(viewer_3D->getRenderWindow());
viewer_3D->addPointCloud(input_cloud, "input_cloud");
ui->PCD_Viewer->update ();
input_cloud->clear();
```
}
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### Author:  [@sankhesh](https://discourse.vtk.org/u/sankhesh)
#### Post date: [July 22, 2022, 2:29pm UTC](https://discourse.vtk.org/t/maximum-number-of-clients-reachederror-in-home-aarju-vtk-7-1-1-rendering-opengl2-vtkxopenglrenderwindow-cxx-line-1497-vtkxopenglrenderwindow-0x555dac8b7280-bad-x-server-connection-display-0-aborting/8977/6 "2022-07-22T14:29:39Z")
It is a little hard to read with the code formatting broken like that. But, can you make sure that you are on the latest vtk version. And also, that `addPointCloud` is not adding new data each frame. Because that will quickly fill up GPU memory.