Hi,
I have the exact same problem. Did you solve this? If yes, please share your solution.
I am using SIM900, and I get this error (only sometimes, and only on some of the modules).
I believe it has to do with power to the SIM card. The attached image is from the documentation. It is suggested to use 100nF for decoupling. It seems that some cases can be overcome with a larger cap, however, even with 100uF, the problem often still appears.
Does anyone have experience with SIMCOM modules or good suggestions here?
BR,
Ulrik