First of all: @Dmitry Dulepov saves the (first part of the) day. Thank you, Mr. Dulepov.
"There is a question that I see several times monthly in TYPO3 mailing lists: "I see an empty (blank) page after XXX. How do I fix it?". Here is the step by step answer:
Go to the Install tool
Select "All configuration"
Set displayErrors to 2
Add your IP address to devIPmask
Now you will see PHP errors that happen. By default these errors are hidden by TYPO3 for security reasons and it causes blank pages. Changing settings above allows to see these errors on your IP address only.
So fix these PHP errors and your site will be back."
I had this problem, namely, after installing Xdebug as instructed in the "Reliable Extensions" book project.
In the Install Tool, "Configuration All", the "displayErrors" parameter has a value of "1", which means:
"Default setting. With this option, you can override the PHP setting 'display_errors'. If devIPmask matches the users IP address the configured 'debugExceptionHandler' is used for exceptions, if not 'productionExceptionHandler' will be used."
We need to change it to "2", which means:
"Display errors only if client matches [SYS][devIPmask]. If devIPmask matches the users IP address the configured 'debugExceptionHandler' is used for exceptions, if not 'productionExceptionHandler' will be used".
Re-opening the "Extension Manager" / "Get Extensions" page, I feel so enlightened; here's my error:
"( ! ) Fatal error: Maximum function nesting level of '100' reached, aborting! in /var/www/buch/typo3_src-6.1.5/typo3/sysext/core/Classes/Utility/GeneralUtility.php on line 1125"
I fixed this - after some googling and detouring - by entering the following line of code in my php.ini file:
xdebug.max_nesting_level = 250
I had a hard time figuring this out because I assumed that this line would already be IN the php.ini, because that's what my phpinfo() was telling me. Apparently the default is used, without an explicit line of code in php.ini, so if you want to change it, you have to write it out yourself.
Next, I was forced to undergo an HOURS-LONG detour in that I returned my edition 1 of "Reliable Typo3 Extensions" and bought the 2nd edition from O'Reilly books. I love the English version of the O'Reilly books site, but unfortunately the German site - which has NO user registration - sucks, and I got the Ebook as link in an email to a PDF... which I was not able to bring over to join my Ebooks on the iPad.
So I settled for working with the book as a PDF on my laptop. But installing the "blog_example" (new, version 1.4) extension provided by the authors or "Reliable Extensions" (wow - the irony...) via download ended up killing my Typo3. I found out that this is because uploading the .zip file of extension as instructed writes the ".zip" part of the file AS PART OF THE EXTENSION KEY, which breaks EVERYTHING. After a LOT of cursing under my breath and combing through lines of code, I was able to get everything running again by:
1) renaming the directory under typo3conf/ext from "blog_example.zip" to "blog_example"
2) getting rid of all references to "blog_example.zip" in typo3conf/LocalConfiguration.php
3) forcibly clearing the cache by deleting the typo3temp directory
I only did all of this after first commenting out some lines of code in the UtilityManager.php so that I could get back into the backend and de-install the (shitty) extension and try to reinstall it from the unzipped version of the directory (which, of course, did not work).
Hi, writers of "Reliable Typos3 extensions": you might want to fix your "blog_example" code AND the typo on page 19 that reads "Um das Modul nutzen zu können, müssen Sie zunächst im TypoScript-Setup Ihrer root-Seite das statische Template BloxExample setup inkludieren". ("In order to use the module, you need to include 'BloxExample' (styles) in the static template of your root page." Because that's BlogExample. At least this crucial instruction is INCLUDED in the 2nd edition of the book: in the first, it was not, basically rendering the appropriate extension of "blog_example" (version 1.3) completely unusable.
Anyway... working with Eclipse and "projects" isn't really working for me today either. Why is it taking minutes to run the debugger on one line of code? Finally I got it working, but I'm irritable and annoyed so the fun of it will be hard to recover. Too many problems with software not written by oneself makes up 90% of the sucky part of programming, I think.