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Apache mod_fastcgi & HTTP/2 Inconsistencies

Posted: Thu May 14, 2026 2:36 pm
by mampsupportmod
We were receiving below across our sites after enabling

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http2_module
in Apache config:
411 Error:

Length Required
A request of the requested method GET requires a valid Content-length.
Apache/2.4.66 (Unix) OpenSSL/1.1.Iw mod_wsgil5.0.2 Python/3.14 mod_fastci/mod_fastgi-

411 Length Required


After investigation we found

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mod_fastcgi
incompatibility with HTTP/2 and produces random 411 errors on browsing. However, current version of MAMP Pro requires FastCGI remain enabled per config:

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# modules that SHOULD be always ON
LoadModule fastcgi_module modules/mod_fastcgi.so
mod_fastcgi is now considered legacy. MAMP needs to move to new version which is

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http2_module
+

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proxy_fcgi_module
and so to allow disabling of fastcgi.


Short term solution is to disable http2_module in Apache config when using fastcgi.