As the message says. Here's what I've done to try to fix the problem without results.
Cleared site cache (multiple times)
Cleared browser cache (multiple times)
Checked GeoBlock (Netherlands isn't blocked)
Tried to update via Joomla update (see screenshots)
Tried G. Chrome, Edge and FireFox browsers.
Can you help me fix this, please? Thanks.
PS On a side note, I was able to update the regular SecurityCheck Pro software without any issues.