Error messages

What does the message "Could not find package..." mean?
Problem The Composer installation of an extension in Magento 2 fails. The following error occurs: Could not find package ... at any version for you...
Tue, 29 Oct, 2019 at 10:35 AM
Why does "no such file or directory" appear when executing Composer?
Problem When trying to execute the following Composer command composer config repositories.VENDOR /path/to/some/package/ this error appears: .....
Wed, 11 Jul, 2018 at 1:58 PM
What does "TypeError: ... is not a function" mean?
This means that a JavaScript function couldn't be found. Maybe customized templates are being used and not all required JavaScript files are load...
Wed, 21 Mar, 2018 at 9:47 AM
What does "Class ... not found" mean?
Problem The following error occurs: PHP Fatal error: Uncaught Error: Class ... not found Cause This problem often occurs when a Magento extension has...
Tue, 11 Dec, 2018 at 3:43 PM
Why are PHP Exceptions (Fatal Error) not written to the log files?
Problem It is suspected that a PHP Exception (Fatal Error) occurs. However, no error message is visible in the browser. In the usual log files of the webse...
Tue, 20 Aug, 2019 at 8:47 AM
What does the error "main.CRITICAL: Broken reference: No element found..." mean?
Problem After installing a Magento 2 module, this error occurs in the checkout: main.CRITICAL: Broken reference: No element found with ID 'checkou...
Thu, 18 Apr, 2019 at 11:19 AM
What does the message "Can't use method return value in write context" mean?
Problem When executing Cronjobs, the following error occurs: Can't use method return value in write context in [...] Cause This message occurs ...
Thu, 24 Aug, 2017 at 10:13 AM
What does "Exception printing is disabled by default for security reasons" mean?
Problem The following message is shown in the browser: Exception printing is disabled by default for security reasons. Error log record number xxxxxxx...
Tue, 1 Oct, 2019 at 2:04 PM
Summary of PHP errors and solutions
A very helpful summary of common PHP errors with solutions can be found here: Reference - What does this error mean in PHP?
Thu, 21 Jun, 2018 at 11:33 AM