When I first installed NextGen Gallery plugin for WordPress I could not get the watermarking working. I read of all sorts of problems with it including FreeType not being installed, permission problems, etc. but everything that I was trying was not resolving my issue. During upload I was not getting any errors so at the time I felt I had little to go on. To make a long story short I finally read a post on WordPress.org that said the watermark image has to be a PNG for it to work. I saved my watermark file as a .png file and sure enough it worked without issue.
The entire error I recieved was: Fatal error: Cannot redeclare tc_post() (previously declared in www/wp-content/plugins/text-control.php:20) in www/wp-content/plugins/text-control/text-control.php on line 33
When upgrading the WordPress plugin text-control I was getting this error when trying to activate text-control. I ended up remembering that the markdown.php had not worked on initial installation so I replaced it with the markdown.php from the WordPress plugin PHP Markdown Extra which resolved my initial issue.
While working on this site I decided to not only have a tag cloud widget but also build out a page that included nothing but a list of all the tags marked for each article. This way someone could click on the tag page I wanted to list all the tags in alphabetical order and look for a specific tag. The WordPress documentation page is awesome so it was fairly easy to find though I had to search the documentation rather than typing in my question on a search engine and locating the answer quickly.
There are a couple settings that may need to be changed when uploading zip files via the NextGen Gallery admin interface within WordPress. The actual plugin notes that php.ini should have the following setting changed from the default of 2M to 20M like below.