Fatal error: Array and string offset access syntax with curly braces is no longer supported

[adamrydza]

Fatal error: Array and string offset access syntax with curly braces is no longer supported in D:\Wordpress\apps\wordpress\htdocs\wp-content\plugins\unyson\framework\extensions\builder\includes\option-types\builder\extends\class-fw-option-type-builder.php on line 353

How can I fix it? I have Wordpress in localhost (bitnami). I installed Unyson and turned on PageBuilder. Then this error popped up. I have it in the admin panel and on the website.

[stacyk]

if you change line 353

from: if (!$this->compression_is_enabled($option) || $input_value{0} === '[') {

to: if (!$this->compression_is_enabled($option) || $input_value[0] === '[') {

I wonder how many other files need to be updated and if Unyson will ever include these updates (it feels gross to override the plugin, but it looks like they aren't actively publishing updates).