Does anyone could share a protocol for divergence time calculation based on nucleotide sequences (plant chloroplast genomes)?

I tried with BEAST but failed to generate the input file xml file by BEAUti.

My potocol as follows;

BEAUTi (V. 1.8)

File-> Import input.nexus data  

@taxa -> ingroup (only known samples: ex: rice & sorghum divergence time: 13mya ) and outgroup

@sites -> HYK (substitution model), Gamma (site heterogeneity model)

@clocks -> strict model

@trees -> yule process

@Prior-> All normal, tmrca (untitled)-> normal (Mean:13 SD; 2) how this value calculated?

                  Ucld.mean -> gamma -> shape: 1000,  scale: 0.001,                         

@MCMC -> length of chain-1,000,000 generation, Echo state – 10,000, log parameter – 1000

 5,000,000 generation, Echo state – 50,000, log parameter – 1000

The Error while generating xml file for BEAST

“ BEAST has terminated with an error. Please select QUIT from the menu.

Parsing error - poorly formed BEAST file, uTb_mfft_nexus 28+1_strict_pri17+2.xml:

Error parsing '' element with id, 'null':

Uniform prior uniformPrior cannot take a bound at infinity, because it returns 1/(high-low) = 1/inf

”

plz  suggest me how to overcome this issue.

Any other protocol you like to suggest?

Many thanks

sam