Modula Watermark and Modula Speed Up.
If you are using both extensions you might encounter issues applying the watermark to some images. If the speed up option was activated before the watermark, we recommend going to your gallery > Speed Up > and change Thumbnail Compression + Lightbox Compression after the watermark was saved. Then view the gallery on the page (to delete the cache from our CDN) and then go back to the gallery > Speed Up > put it back how it was > save.
If the watermark take too long to be applied please go to your WP dashboard > Tools > Site Health > Info > Server. You will see there PHP time limit.
You need to change the max_execution_time. Please see the information here: https://thimpress.com/knowledge-base/how-to-increase-maximum-execution-time-for-wordpress-site/
We recommend to set it at 360.