Prior versions of PHD2 (v2.6.13) using INDI client version 2.0 were apparently compatible with INDIGO servers, but when the INDI client was updated to v2.1.5 and now 2.1.6 in PHD2 v2.6.14 INDIGO camera image capture is no longer working.
The debug log shows:
20:38:23.982 00.000 16244 Alert: Unknown image format:
indicating that PHD2 sees an empty image format when it is expecting the format to be .fits.