Frequent Error Messages for PHP Scripts

Here we have compiled an overview of script errors frequently displayed in browsers or server-side error messages that occur in connection with scripts. Your message indicates problems with MySQL (e.g.'Database Error','unable to connect to database db12345678')? Please read the article Common Error Messages in MySQL.

What does it mean? What can I do?    
Error 500: Internal Server Error This error usually occurs in the following situations: 1. the limits for process runtimes or executable processes were exceeded to execute the script. 2. a command in a.htaccess file (e.g. with a rewrite rule) is incorrect. 3. an unexpected server-side error has occurred. Note the script limits set for web hosting packages. 2 Check your.htaccess files for typing errors. Just one missing character is enough to get an error message. We have compiled tips for avoiding errors in rewrite rules for you in the help article Notes for creating rewrite rules. You parse in a.htaccess to a certain PHP version? 3. wait a few minutes, clear the cache of your web browser and reload the page. Continues the error message: Check the 1&1 IONOS status page for any reported faults. If you cannot find anything here, please contact our support.  
Parse error: syntax error, unexpected [...] in ... Errors in the syntax (the programming code) of the script have occurred Check whether your script code contains missing or incorrect characters or commands. Tip: Copy the code into an editor such as Notepad ++ and activate syntax highlighting in the settings. This function highlights commands in color, making it easier to find errors.  
Fatal error: Out of memory (allocated 123456789) (tried to allocate 29360129 bytes) in /test.php on line 9 The maximum memory limit for executing a script has been reached. Please note the script limits in the article Which PHP settings can I change. You have optimized the scripts with regard to the utilization of the memory limit, but the error still occurs? In these cases, we recommend switching to a larger WebHosting package or to a 1&1 IONOS Managed Server.  
Fatal error: Maximum execution time exceeded The limit for script process runtimes has been reached. If this error occurs frequently, check the performance request of your script. Look for alternative applications that could do the functions of your script with less computing time. Alternatively, we would be happy to advise you on the choice of a more powerful WebHosting package or 1&1 IONOS Managed Server.  
Warning: fopen(...): failed to open stream: Permission denied in... A file permission problem with the fopen function has occurred If the script tries to open another file or another script using the fopen function, it must have the required server rights. If this is not the case, this error may occur. Check the read, write and execute permissions (chmod) of the script and adjust them accordingly. Further information can be found in the fopen documentation at PHP.net.
Fatal error: main()[function.require]: Failed opening required... The script needs another script to execute a function. Check whether the file required to call the function exists and whether the directory path listed there is correct. Adjust the path specification accordingly. For more information, refer to the documentation on the'require' function at PHP.net  

The new 1&1 IONOS Help Center with instructions and information about our domain products and services.