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How I Debugged a phpMyAdmin 500 Error While Importing a Large SQL File on Laragon

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I recently ran into a weird issue while working on a Laravel project on Windows using Laragon.

Everything was working fine until I tried to import a database through phpMyAdmin.

Instead of an SQL error, phpMyAdmin simply returned:

Internal Server Error
The server encountered an internal error or misconfiguration...
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No useful message. Just HTTP 500.

My SQL file was around 97 MB, so at first I thought it was probably a PHP upload limit issue.

It wasn't that simple.

Here is how I debugged it.

1. Check which PHP configuration is actually running

From Laragon Terminal:

php --ini
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Then I checked the important error settings:

php.exe -r "echo 'error_log=' . ini_get('error_log') . PHP_EOL;"
php.exe -r "echo 'log_errors=' . ini_get('log_errors') . PHP_EOL;"
php.exe -r "echo 'display_errors=' . ini_get('display_errors') . PHP_EOL;"
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My output was:

error_log=D:/C-data/laragon/tmp/php_errors.log
log_errors=1
display_errors=1
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One small Laragon/Git Bash issue I also found was:

type php
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returned:

php is aliased to `winpty php.exe'
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Because of that, commands like:

php -i | grep ...
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sometimes returned:

stdout is not a tty
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Using php.exe directly avoids that problem.

2. Check the PHP error log

My PHP error log was:

D:/C-data/laragon/tmp/php_errors.log
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I reproduced the import error and checked it:

tail -n 50 /d/C-data/laragon/tmp/php_errors.log
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Nothing useful appeared.

That was an important clue.

3. Make sure browser PHP and CLI PHP use the same php.ini

I created a temporary file:

<?php phpinfo();
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Then opened it through the browser.

Important values were:

Server API: CGI/FastCGI
PHP Version: 8.4.4
Loaded Configuration File:
D:\C-data\laragon\bin\php\php-8.4.4-nts-Win32-vs17-x64\php.ini
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My PHP limits were already high enough:

upload_max_filesize = 512M
post_max_size = 512M
memory_limit = 512M
max_execution_time = 36000
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So the 97 MB SQL file should have been allowed by PHP.

4. Check Apache logs

I located the Apache error log with:

grep -Ri "ErrorLog" /d/C-data/laragon/etc/apache2 /d/C-data/laragon/bin/apache 2>/dev/null
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In my case:

D:/C-data/laragon/bin/apache/httpd-2.4.54-win64-VS16/logs/error.log
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Then:

tail -n 50 /d/C-data/laragon/bin/apache/httpd-2.4.54-win64-VS16/logs/error.log
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Still nothing useful.

So I checked the access log:

tail -n 30 /d/C-data/laragon/bin/apache/httpd-2.4.54-win64-VS16/logs/access.log
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And finally found:

POST /phpmyadmin/index.php?route=/import HTTP/1.1" 500 530
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So the failure was definitely happening during the phpMyAdmin import request.

5. Check Laragon's FastCGI request limit

Because Laragon was using mod_fcgid, I searched its config:

grep -RniE "Fcgid|Timeout|LogLevel" \
/d/C-data/laragon/etc/apache2 \
/d/C-data/laragon/bin/apache/httpd-2.4.54-win64-VS16/conf 2>/dev/null
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That led me to:

D:\C-data\laragon\etc\apache2\fcgid.conf
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Inside I found:

FcgidIOTimeout 36000
FcgidConnectTimeout 16
FcgidMaxRequestLen 81310720
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The important one was:

FcgidMaxRequestLen 81310720
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That is only around 77.5 MiB.

My SQL file was:

ls -lh "/c/Users/Asus/Downloads/shabujglobal-crm (1).sql"
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Output:

97M
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So PHP allowed 512M, but Apache FastCGI only allowed around 77.5 MiB.

That mismatch can cause the request to fail before phpMyAdmin can properly process the upload.

6. Increase FcgidMaxRequestLen

Open:

D:\C-data\laragon\etc\apache2\fcgid.conf
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Change:

FcgidMaxRequestLen 81310720
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to:

FcgidMaxRequestLen 536870912
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That gives FastCGI a 512 MiB request limit.

Then:

Save → Laragon → Restart All
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and retry the import.

7. If the next error is “Maximum execution time of 300 seconds exceeded”

After fixing the request-size limit, I hit another possible bottleneck:

Fatal error: Maximum execution time of 300 seconds exceeded
in DbiMysqli.php
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If you see this, do not edit DbiMysqli.php. That is only where the timeout becomes visible.

Instead, open:

D:\C-data\laragon\etc\apps\phpMyAdmin\config.inc.php
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and add:

$cfg['ExecTimeLimit'] = 0;
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If the file contains a closing ?>, add the line before it.

Then:

Save → Laragon → Restart All
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and retry the import.

Setting ExecTimeLimit to 0 removes phpMyAdmin's execution-time limit for operations such as large imports.

In my debugging session, this was the latest issue I reached. I had not yet fully confirmed the final import after changing this setting, so treat this as the next configuration to verify if your import dies exactly at 300 seconds.

The main lesson

When phpMyAdmin gives you a generic 500 Internal Server Error while importing a large SQL file on Laragon, don't only check:

upload_max_filesize
post_max_size
memory_limit
max_execution_time
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Also check these two layers:

FcgidMaxRequestLen
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and:

$cfg['ExecTimeLimit']
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In my case, the debugging path was basically:

97 MB SQL file
↓
PHP limits looked fine
↓
No useful PHP error log
↓
Apache access log confirmed /import returned 500
↓
FastCGI request limit was smaller than the SQL file
↓
After that, phpMyAdmin's 300-second execution limit became the next bottleneck
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That is the part that can easily be missed: PHP may allow a large upload while Apache/FastCGI or phpMyAdmin still blocks it for a completely different reason.

And if you create a temporary phpinfo() file while debugging, delete it afterward.

Source: dev.to

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