I had gcal installed to manage some crons.
Since today, 18:18, I’m getting following errror:
2019-06-18 18:18:08.850 [ERROR] [io.gcal.internal.GCalEventDownloader] - Event fetch failed: 429 unknown
<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><title>Sorry...</title><style> body { font-family: verdana, arial, sans-serif; background-color: #fff; color: #000; }</style></head><body><div><table><tr><td><b><font face=sans-serif size=10><font color=#4285f4>G</font><font color=#ea4335>o</font><font color=#fbbc05>o</font><font color=#4285f4>g</font><font color=#34a853>l</font><font color=#ea4335>e</font></font></b></td><td style="text-align: left; vertical-align: bottom; padding-bottom: 15px; width: 50%"><div style="border-bottom: 1px solid #dfdfdf;">Sorry...</div></td></tr></table></div><div style="margin-left: 4em;"><h1>We're sorry...</h1><p>... but your computer or network may be sending automated queries. To protect our users, we can't process your request right now.</p></div><div style="margin-left: 4em;">See <a href="https://support.google.com/websearch/answer/86640">Google Help</a> for more information.<br/><br/></div><div style="text-align: center; border-top: 1px solid #dfdfdf;"><a href="https://www.google.com">Google Home</a></div></body></html>
2019-06-18 18:43:10.294 [ERROR] [io.gcal.internal.GCalEventDownloader] - Event fetch failed: 429 unknown
<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><title>Sorry...</title><style> body { font-family: verdana, arial, sans-serif; background-color: #fff; color: #000; }</style></head><body><div><table><tr><td><b><font face=sans-serif size=10><font color=#4285f4>G</font><font color=#ea4335>o</font><font color=#fbbc05>o</font><font color=#4285f4>g</font><font color=#34a853>l</font><font color=#ea4335>e</font></font></b></td><td style="text-align: left; vertical-align: bottom; padding-bottom: 15px; width: 50%"><div style="border-bottom: 1px solid #dfdfdf;">Sorry...</div></td></tr></table></div><div style="margin-left: 4em;"><h1>We're sorry...</h1><p>... but your computer or network may be sending automated queries. To protect our users, we can't process your request right now.</p></div><div style="margin-left: 4em;">See <a href="https://support.google.com/websearch/answer/86640">Google Help</a> for more information.<br/><br/></div><div style="text-align: center; border-top: 1px solid #dfdfdf;"><a href="https://www.google.com">Google Home</a></div></body></html>
2019-06-18 18:48:10.924 [ERROR] [io.gcal.internal.GCalEventDownloader] - Event fetch failed: 429 unknown
<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><title>Sorry...</title><style> body { font-family: verdana, arial, sans-serif; background-color: #fff; color: #000; }</style></head><body><div><table><tr><td><b><font face=sans-serif size=10><font color=#4285f4>G</font><font color=#ea4335>o</font><font color=#fbbc05>o</font><font color=#4285f4>g</font><font color=#34a853>l</font><font color=#ea4335>e</font></font></b></td><td style="text-align: left; vertical-align: bottom; padding-bottom: 15px; width: 50%"><div style="border-bottom: 1px solid #dfdfdf;">Sorry...</div></td></tr></table></div><div style="margin-left: 4em;"><h1>We're sorry...</h1><p>... but your computer or network may be sending automated queries. To protect our users, we can't process your request right now.</p></div><div style="margin-left: 4em;">See <a href="https://support.google.com/websearch/answer/86640">Google Help</a> for more information.<br/><br/></div><div style="text-align: center; border-top: 1px solid #dfdfdf;"><a href="https://www.google.com">Google Home</a></div></body></html>
Guess that google tries to limit their traffic a bit. 
It’s nog a big deal for me, since I only had 2 events, and I’ve migrate this to local crons now.
But if I can help to test/solve/… this, let me know…