Getting random ERC errors

I am creating a board with 96 WS2813-mini LEDs broken down into 9 rows. Since there is so much duplication I have used copy block/past and duplicate block. I am now seeing random ERC errors about unconnected pins even though they are connected. If I move the traces elsewhere it often fixes it, but then another random error pops up.

My project is at

Additionally, even though all footprints have been assigned, nothing shows up in the PCB editor.

This is with 5.1.2, wxWidgets 3.0.3 running on OpenSuSE 15.0.
Application: kicad
Version: 5.1.2-5.1.2, release build
wxWidgets 3.0.3
libcurl/7.60.0 OpenSSL/1.1.0i zlib/1.2.11 libidn2/2.0.4 libpsl/0.20.1 (+libidn2/2.0.4) libssh/0.7.5/openssl/zlib nghttp2/1.31.1
Platform: Linux 4.12.14-lp150.12.58-default x86_64, 64 bit, Little endian, wxGTK
Build Info:
wxWidgets: 3.0.3 (wchar_t,STL containers,compatible with 2.8) GTK+ 2.24
Boost: 1.66.0
OpenCASCADE Community Edition: 6.9.1
Curl: 7.59.0
Compiler: GCC 7.3.1 with C++ ABI 1011

Build settings:

note by admin corrected use of ERC vs DRC: ERC is the electrical rule check of eeschema, DRC is the design rule check of pcbnew

If you are talking about GND and VCC pins, they are not connected. When a pin is connected to a wire, the little circle at the end of the pin vanishes.

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In my case, EESCHEMA is showing that it IS connected, the junction is present.

Could you then tell us which is the error message you get?

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This has been marked and confirmed as a bug.

The answer was in the FAQ

I do not see the bug.
As Pedro (and Launchpad) already mentioned it is just the missing power flags.
The amount of LED’s, the story around it, and that KiCad picks just a random pin to show the error all make it more confusing.

When I tried to drag a symbol with “g”, the wire bend at the expected location, which clearly shows they are connected. (Press Esc to cancel the drag).

When I added the PWR_FLAG to both +5V and GND the ERC errors dissapeared.
With the PWR_FLAG’s it looks like:

If you often have schematics with many repeating symbols, you may want to look into Skidl. It is a Python library to help with generating netlists from code. It is a sort of VHDL for schematics.
There are also various scripts for generating repetitive stuff on a PCB. Either in Pcbnew (Replicate Plugin) or completely from scripts without Pcbnew ( Go get Skidl klock example).

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