Internal Server Error

What would cause this error whens editing on the front end:

Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster@17025.ourbizport.com to inform them of the time this error occurred, and the actions you performed just before this error.
More information about this error may be available in the server error log.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Only one item (others edit fine).
Does NOT occur on back end.

Current php Info Settings:
upload_max_filesize = 32M
post_max_size = 64M

Thank you.

Hello

you need to look at your web server error log

it can be e.g. a non-allowed directive in .htaccess or syntax error in it
or other issue, related or not related to FLEXIcontent

1) I set Global Confg > Use URL rewriting to YES
2) Change htaccess.txt to .htaccess
3) Edited the offending item

Editing on the back end works fine - as it did before...

Now when editing on the front end it does not give me an Internal Server Error ...but
"Save & Return" Saves and resumes editing
"Save & Preview" Saves and resumes editing
"Cancel" refreshes the screen and resumes editing

I have a client that has been using FlexiConent since 2012 using Joomla 2.5 - and they love it - in fact their business depends on it. I'm trying to understand and configure FlexiContent 3.0.14 under J! 3.5.1 so I can upgrade them. My testing is under the same server / hosting configuration as their live system.

No offense here - But I'm getting so many "weird" errors that I have not seen before... Is 3.0.14-rc2a ready?

Thanks again for your time.

Hello

yes, v3.0.14-rc2a is our latest official version

about "Internal Server Error"
it is not a specific error
- the real message does exist in the web-server log

if you don't know where the log is located / or how to read it,
- a question to your web-hosting provide asking where the log is would help you find

since you have a test-site you can also try this version:
github.com/FLEXIcontent/flexicontent-cck/tree/3.0.x-stable

click download zip and install via Joomla extension manager into the testing web-site

the new version will probably not change the internal server error
because the error is probably related to your web-server configuration
- you need to find the real error in the logs