Here my problem and solution for me.
Because joomla encourage you to use php-7 I think this is a problem more people can get.
In the version with php-5 all was okee. After switching to php-7 the captcha-image did not show.
First I could not find the solution. On my live site Captcha image shows in php5 and not in php7. I put my site local with XAMP with php7 and it workt. So it has to be something with the php on my server. So I google for captcha image not showing and read about the GD libary.
I did not realise that for every php version you have to install the GD libery.
On my server I installed php but without GD.
Installing GD fot php7 did the trick.
Have a nice day!
Rolf
Because joomla encourage you to use php-7 I think this is a problem more people can get.
In the version with php-5 all was okee. After switching to php-7 the captcha-image did not show.
First I could not find the solution. On my live site Captcha image shows in php5 and not in php7. I put my site local with XAMP with php7 and it workt. So it has to be something with the php on my server. So I google for captcha image not showing and read about the GD libary.
I did not realise that for every php version you have to install the GD libery.
On my server I installed php but without GD.
Installing GD fot php7 did the trick.
Have a nice day!
Rolf